[25] | 1 | /* |
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| 2 | * tclIOGT.c -- |
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| 3 | * |
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| 4 | * Implements a generic transformation exposing the underlying API at the |
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| 5 | * script level. Contributed by Andreas Kupries. |
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| 6 | * |
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| 7 | * Copyright (c) 2000 Ajuba Solutions |
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| 8 | * Copyright (c) 1999-2000 Andreas Kupries (a.kupries@westend.com) |
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| 9 | * |
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| 10 | * See the file "license.terms" for information on usage and redistribution of |
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| 11 | * this file, and for a DISCLAIMER OF ALL WARRANTIES. |
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| 12 | * |
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| 13 | * CVS: $Id: tclIOGT.c,v 1.20 2007/12/13 15:23:18 dgp Exp $ |
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| 14 | */ |
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| 15 | |
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| 16 | #include "tclInt.h" |
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| 17 | #include "tclIO.h" |
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| 18 | |
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| 19 | /* |
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| 20 | * Forward declarations of internal procedures. First the driver procedures of |
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| 21 | * the transformation. |
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| 22 | */ |
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| 23 | |
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| 24 | static int TransformBlockModeProc(ClientData instanceData, |
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| 25 | int mode); |
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| 26 | static int TransformCloseProc(ClientData instanceData, |
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| 27 | Tcl_Interp *interp); |
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| 28 | static int TransformInputProc(ClientData instanceData, char *buf, |
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| 29 | int toRead, int *errorCodePtr); |
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| 30 | static int TransformOutputProc(ClientData instanceData, |
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| 31 | const char *buf, int toWrite, int *errorCodePtr); |
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| 32 | static int TransformSeekProc(ClientData instanceData, long offset, |
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| 33 | int mode, int *errorCodePtr); |
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| 34 | static int TransformSetOptionProc(ClientData instanceData, |
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| 35 | Tcl_Interp *interp, const char *optionName, |
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| 36 | const char *value); |
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| 37 | static int TransformGetOptionProc(ClientData instanceData, |
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| 38 | Tcl_Interp *interp, const char *optionName, |
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| 39 | Tcl_DString *dsPtr); |
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| 40 | static void TransformWatchProc(ClientData instanceData, int mask); |
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| 41 | static int TransformGetFileHandleProc(ClientData instanceData, |
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| 42 | int direction, ClientData *handlePtr); |
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| 43 | static int TransformNotifyProc(ClientData instanceData, int mask); |
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| 44 | static Tcl_WideInt TransformWideSeekProc(ClientData instanceData, |
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| 45 | Tcl_WideInt offset, int mode, int *errorCodePtr); |
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| 46 | |
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| 47 | /* |
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| 48 | * Forward declarations of internal procedures. Secondly the procedures for |
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| 49 | * handling and generating fileeevents. |
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| 50 | */ |
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| 51 | |
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| 52 | static void TransformChannelHandlerTimer(ClientData clientData); |
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| 53 | |
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| 54 | /* |
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| 55 | * Forward declarations of internal procedures. Third, helper procedures |
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| 56 | * encapsulating essential tasks. |
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| 57 | */ |
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| 58 | |
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| 59 | typedef struct TransformChannelData TransformChannelData; |
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| 60 | |
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| 61 | static int ExecuteCallback(TransformChannelData *ctrl, |
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| 62 | Tcl_Interp *interp, unsigned char *op, |
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| 63 | unsigned char *buf, int bufLen, int transmit, |
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| 64 | int preserve); |
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| 65 | |
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| 66 | /* |
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| 67 | * Action codes to give to 'ExecuteCallback' (argument 'transmit'), telling |
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| 68 | * the procedure what to do with the result of the script it calls. |
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| 69 | */ |
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| 70 | |
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| 71 | #define TRANSMIT_DONT 0 /* No transfer to do. */ |
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| 72 | #define TRANSMIT_DOWN 1 /* Transfer to the underlying channel. */ |
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| 73 | #define TRANSMIT_SELF 2 /* Transfer into our channel. */ |
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| 74 | #define TRANSMIT_IBUF 3 /* Transfer to internal input buffer. */ |
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| 75 | #define TRANSMIT_NUM 4 /* Transfer number to 'maxRead'. */ |
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| 76 | |
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| 77 | /* |
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| 78 | * Codes for 'preserve' of 'ExecuteCallback'. |
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| 79 | */ |
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| 80 | |
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| 81 | #define P_PRESERVE 1 |
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| 82 | #define P_NO_PRESERVE 0 |
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| 83 | |
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| 84 | /* |
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| 85 | * Strings for the action codes delivered to the script implementing a |
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| 86 | * transformation. Argument 'op' of 'ExecuteCallback'. |
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| 87 | */ |
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| 88 | |
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| 89 | #define A_CREATE_WRITE (UCHARP("create/write")) |
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| 90 | #define A_DELETE_WRITE (UCHARP("delete/write")) |
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| 91 | #define A_FLUSH_WRITE (UCHARP("flush/write")) |
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| 92 | #define A_WRITE (UCHARP("write")) |
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| 93 | |
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| 94 | #define A_CREATE_READ (UCHARP("create/read")) |
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| 95 | #define A_DELETE_READ (UCHARP("delete/read")) |
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| 96 | #define A_FLUSH_READ (UCHARP("flush/read")) |
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| 97 | #define A_READ (UCHARP("read")) |
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| 98 | |
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| 99 | #define A_QUERY_MAXREAD (UCHARP("query/maxRead")) |
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| 100 | #define A_CLEAR_READ (UCHARP("clear/read")) |
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| 101 | |
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| 102 | /* |
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| 103 | * Management of a simple buffer. |
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| 104 | */ |
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| 105 | |
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| 106 | typedef struct ResultBuffer ResultBuffer; |
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| 107 | |
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| 108 | static inline void ResultClear(ResultBuffer *r); |
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| 109 | static inline void ResultInit(ResultBuffer *r); |
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| 110 | static inline int ResultEmpty(ResultBuffer *r); |
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| 111 | static inline int ResultCopy(ResultBuffer *r, unsigned char *buf, |
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| 112 | size_t toRead); |
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| 113 | static inline void ResultAdd(ResultBuffer *r, unsigned char *buf, |
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| 114 | size_t toWrite); |
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| 115 | |
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| 116 | /* |
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| 117 | * This structure describes the channel type structure for Tcl-based |
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| 118 | * transformations. |
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| 119 | */ |
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| 120 | |
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| 121 | static Tcl_ChannelType transformChannelType = { |
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| 122 | "transform", /* Type name. */ |
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| 123 | TCL_CHANNEL_VERSION_5, /* v5 channel */ |
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| 124 | TransformCloseProc, /* Close proc. */ |
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| 125 | TransformInputProc, /* Input proc. */ |
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| 126 | TransformOutputProc, /* Output proc. */ |
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| 127 | TransformSeekProc, /* Seek proc. */ |
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| 128 | TransformSetOptionProc, /* Set option proc. */ |
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| 129 | TransformGetOptionProc, /* Get option proc. */ |
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| 130 | TransformWatchProc, /* Initialize notifier. */ |
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| 131 | TransformGetFileHandleProc, /* Get OS handles out of channel. */ |
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| 132 | NULL, /* close2proc */ |
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| 133 | TransformBlockModeProc, /* Set blocking/nonblocking mode.*/ |
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| 134 | NULL, /* Flush proc. */ |
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| 135 | TransformNotifyProc, /* Handling of events bubbling up. */ |
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| 136 | TransformWideSeekProc, /* Wide seek proc. */ |
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| 137 | NULL, /* Thread action. */ |
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| 138 | NULL, /* Truncate. */ |
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| 139 | }; |
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| 140 | |
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| 141 | /* |
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| 142 | * Possible values for 'flags' field in control structure, see below. |
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| 143 | */ |
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| 144 | |
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| 145 | #define CHANNEL_ASYNC (1<<0) /* Non-blocking mode. */ |
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| 146 | |
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| 147 | /* |
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| 148 | * Definition of the structure containing the information about the internal |
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| 149 | * input buffer. |
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| 150 | */ |
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| 151 | |
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| 152 | struct ResultBuffer { |
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| 153 | unsigned char *buf; /* Reference to the buffer area. */ |
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| 154 | size_t allocated; /* Allocated size of the buffer area. */ |
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| 155 | size_t used; /* Number of bytes in the buffer, no more than |
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| 156 | * number allocated. */ |
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| 157 | }; |
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| 158 | |
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| 159 | /* |
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| 160 | * Additional bytes to allocate during buffer expansion. |
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| 161 | */ |
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| 162 | |
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| 163 | #define INCREMENT 512 |
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| 164 | |
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| 165 | /* |
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| 166 | * Number of milliseconds to wait before firing an event to flush out |
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| 167 | * information waiting in buffers (fileevent support). |
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| 168 | */ |
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| 169 | |
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| 170 | #define FLUSH_DELAY 5 |
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| 171 | |
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| 172 | /* |
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| 173 | * Convenience macro to make some casts easier to use. |
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| 174 | */ |
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| 175 | |
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| 176 | #define UCHARP(x) ((unsigned char *) (x)) |
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| 177 | |
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| 178 | /* |
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| 179 | * Definition of a structure used by all transformations generated here to |
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| 180 | * maintain their local state. |
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| 181 | */ |
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| 182 | |
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| 183 | struct TransformChannelData { |
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| 184 | /* |
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| 185 | * General section. Data to integrate the transformation into the channel |
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| 186 | * system. |
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| 187 | */ |
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| 188 | |
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| 189 | Tcl_Channel self; /* Our own Channel handle. */ |
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| 190 | int readIsFlushed; /* Flag to note whether in.flushProc was |
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| 191 | * called or not. */ |
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| 192 | int flags; /* Currently CHANNEL_ASYNC or zero. */ |
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| 193 | int watchMask; /* Current watch/event/interest mask. */ |
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| 194 | int mode; /* Mode of parent channel, OR'ed combination |
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| 195 | * of TCL_READABLE, TCL_WRITABLE. */ |
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| 196 | Tcl_TimerToken timer; /* Timer for automatic flushing of information |
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| 197 | * sitting in an internal buffer. Required for |
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| 198 | * full fileevent support. */ |
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| 199 | |
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| 200 | /* |
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| 201 | * Transformation specific data. |
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| 202 | */ |
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| 203 | |
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| 204 | int maxRead; /* Maximum allowed number of bytes to read, as |
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| 205 | * given to us by the Tcl script implementing |
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| 206 | * the transformation. */ |
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| 207 | Tcl_Interp *interp; /* Reference to the interpreter which created |
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| 208 | * the transformation. Used to execute the |
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| 209 | * code below. */ |
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| 210 | Tcl_Obj *command; /* Tcl code to execute for a buffer */ |
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| 211 | ResultBuffer result; /* Internal buffer used to store the result of |
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| 212 | * a transformation of incoming data. Also |
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| 213 | * serves as buffer of all data not yet |
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| 214 | * consumed by the reader. */ |
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| 215 | }; |
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| 216 | |
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| 217 | /* |
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| 218 | *---------------------------------------------------------------------- |
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| 219 | * |
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| 220 | * TclChannelTransform -- |
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| 221 | * |
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| 222 | * Implements the Tcl "testchannel transform" debugging command. This is |
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| 223 | * part of the testing environment. This sets up a tcl script (cmdObjPtr) |
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| 224 | * to be used as a transform on the channel. |
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| 225 | * |
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| 226 | * Results: |
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| 227 | * A standard Tcl result. |
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| 228 | * |
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| 229 | * Side effects: |
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| 230 | * None. |
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| 231 | * |
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| 232 | *---------------------------------------------------------------------- |
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| 233 | */ |
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| 234 | |
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| 235 | /* ARGSUSED */ |
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| 236 | int |
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| 237 | TclChannelTransform( |
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| 238 | Tcl_Interp *interp, /* Interpreter for result. */ |
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| 239 | Tcl_Channel chan, /* Channel to transform. */ |
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| 240 | Tcl_Obj *cmdObjPtr) /* Script to use for transform. */ |
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| 241 | { |
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| 242 | Channel *chanPtr; /* The actual channel. */ |
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| 243 | ChannelState *statePtr; /* State info for channel. */ |
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| 244 | int mode; /* Read/write mode of the channel. */ |
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| 245 | TransformChannelData *dataPtr; |
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| 246 | Tcl_DString ds; |
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| 247 | |
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| 248 | if (chan == NULL) { |
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| 249 | return TCL_ERROR; |
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| 250 | } |
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| 251 | |
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| 252 | chanPtr = (Channel *) chan; |
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| 253 | statePtr = chanPtr->state; |
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| 254 | chanPtr = statePtr->topChanPtr; |
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| 255 | chan = (Tcl_Channel) chanPtr; |
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| 256 | mode = (statePtr->flags & (TCL_READABLE|TCL_WRITABLE)); |
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| 257 | |
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| 258 | /* |
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| 259 | * Now initialize the transformation state and stack it upon the specified |
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| 260 | * channel. One of the necessary things to do is to retrieve the blocking |
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| 261 | * regime of the underlying channel and to use the same for us too. |
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| 262 | */ |
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| 263 | |
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| 264 | dataPtr = (TransformChannelData *) ckalloc(sizeof(TransformChannelData)); |
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| 265 | |
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| 266 | Tcl_DStringInit(&ds); |
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| 267 | Tcl_GetChannelOption(interp, chan, "-blocking", &ds); |
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| 268 | dataPtr->readIsFlushed = 0; |
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| 269 | dataPtr->flags = 0; |
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| 270 | if (ds.string[0] == '0') { |
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| 271 | dataPtr->flags |= CHANNEL_ASYNC; |
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| 272 | } |
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| 273 | Tcl_DStringFree(&ds); |
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| 274 | |
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| 275 | dataPtr->self = chan; |
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| 276 | dataPtr->watchMask = 0; |
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| 277 | dataPtr->mode = mode; |
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| 278 | dataPtr->timer = NULL; |
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| 279 | dataPtr->maxRead = 4096; /* Initial value not relevant. */ |
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| 280 | dataPtr->interp = interp; |
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| 281 | dataPtr->command = cmdObjPtr; |
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| 282 | Tcl_IncrRefCount(dataPtr->command); |
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| 283 | |
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| 284 | ResultInit(&dataPtr->result); |
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| 285 | |
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| 286 | dataPtr->self = Tcl_StackChannel(interp, &transformChannelType, dataPtr, |
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| 287 | mode, chan); |
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| 288 | if (dataPtr->self == NULL) { |
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| 289 | Tcl_AppendResult(interp, "\nfailed to stack channel \"", |
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| 290 | Tcl_GetChannelName(chan), "\"", NULL); |
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| 291 | Tcl_DecrRefCount(dataPtr->command); |
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| 292 | ResultClear(&dataPtr->result); |
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| 293 | ckfree((char *) dataPtr); |
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| 294 | return TCL_ERROR; |
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| 295 | } |
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| 296 | |
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| 297 | /* |
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| 298 | * At last initialize the transformation at the script level. |
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| 299 | */ |
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| 300 | |
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| 301 | if ((dataPtr->mode & TCL_WRITABLE) && ExecuteCallback(dataPtr, NULL, |
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| 302 | A_CREATE_WRITE, NULL, 0, TRANSMIT_DONT, P_NO_PRESERVE) != TCL_OK){ |
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| 303 | Tcl_UnstackChannel(interp, chan); |
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| 304 | return TCL_ERROR; |
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| 305 | } |
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| 306 | |
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| 307 | if ((dataPtr->mode & TCL_READABLE) && ExecuteCallback(dataPtr, NULL, |
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| 308 | A_CREATE_READ, NULL, 0, TRANSMIT_DONT, P_NO_PRESERVE) != TCL_OK) { |
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| 309 | ExecuteCallback(dataPtr, NULL, A_DELETE_WRITE, NULL, 0, TRANSMIT_DONT, |
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| 310 | P_NO_PRESERVE); |
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| 311 | Tcl_UnstackChannel(interp, chan); |
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| 312 | return TCL_ERROR; |
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| 313 | } |
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| 314 | |
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| 315 | return TCL_OK; |
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| 316 | } |
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| 317 | |
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| 318 | /* |
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| 319 | *---------------------------------------------------------------------- |
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| 320 | * |
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| 321 | * ExecuteCallback -- |
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| 322 | * |
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| 323 | * Executes the defined callback for buffer and operation. |
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| 324 | * |
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| 325 | * Side effects: |
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| 326 | * As of the executed tcl script. |
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| 327 | * |
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| 328 | * Result: |
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| 329 | * A standard TCL error code. In case of an error a message is left in |
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| 330 | * the result area of the specified interpreter. |
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| 331 | * |
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| 332 | *---------------------------------------------------------------------- |
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| 333 | */ |
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| 334 | |
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| 335 | static int |
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| 336 | ExecuteCallback( |
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| 337 | TransformChannelData *dataPtr, |
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| 338 | /* Transformation with the callback. */ |
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| 339 | Tcl_Interp *interp, /* Current interpreter, possibly NULL. */ |
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| 340 | unsigned char *op, /* Operation invoking the callback. */ |
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| 341 | unsigned char *buf, /* Buffer to give to the script. */ |
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| 342 | int bufLen, /* And its length. */ |
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| 343 | int transmit, /* Flag, determines whether the result of the |
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| 344 | * callback is sent to the underlying channel |
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| 345 | * or not. */ |
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| 346 | int preserve) /* Flag. If true the procedure will preserve |
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| 347 | * the result state of all accessed |
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| 348 | * interpreters. */ |
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| 349 | { |
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| 350 | Tcl_Obj *resObj; /* See below, switch (transmit). */ |
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| 351 | int resLen; |
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| 352 | unsigned char *resBuf; |
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| 353 | Tcl_InterpState state = NULL; |
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| 354 | int res = TCL_OK; |
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| 355 | Tcl_Obj *command = Tcl_DuplicateObj(dataPtr->command); |
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| 356 | |
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| 357 | /* |
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| 358 | * Step 1, create the complete command to execute. Do this by appending |
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| 359 | * operation and buffer to operate upon to a copy of the callback |
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| 360 | * definition. We *cannot* create a list containing 3 objects and then use |
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| 361 | * 'Tcl_EvalObjv', because the command may contain additional prefixed |
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| 362 | * arguments. Feather's curried commands would come in handy here. |
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| 363 | */ |
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| 364 | |
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| 365 | if (preserve == P_PRESERVE) { |
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| 366 | state = Tcl_SaveInterpState(dataPtr->interp, res); |
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| 367 | } |
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| 368 | |
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| 369 | Tcl_IncrRefCount(command); |
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| 370 | res = Tcl_ListObjAppendElement(dataPtr->interp, command, |
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| 371 | Tcl_NewStringObj((char *) op, -1)); |
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| 372 | if (res != TCL_OK) { |
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| 373 | goto cleanup; |
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| 374 | } |
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| 375 | |
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| 376 | /* |
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| 377 | * Use a byte-array to prevent the misinterpretation of binary data coming |
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| 378 | * through as UTF while at the tcl level. |
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| 379 | */ |
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| 380 | |
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| 381 | res = Tcl_ListObjAppendElement(dataPtr->interp, command, |
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| 382 | Tcl_NewByteArrayObj(buf, bufLen)); |
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| 383 | if (res != TCL_OK) { |
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| 384 | goto cleanup; |
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| 385 | } |
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| 386 | |
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| 387 | /* |
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| 388 | * Step 2, execute the command at the global level of the interpreter used |
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| 389 | * to create the transformation. Destroy the command afterward. If an |
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| 390 | * error occured and the current interpreter is defined and not equal to |
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| 391 | * the interpreter for the callback, then copy the error message into |
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| 392 | * current interpreter. Don't copy if in preservation mode. |
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| 393 | */ |
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| 394 | |
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| 395 | res = Tcl_EvalObjEx(dataPtr->interp, command, TCL_EVAL_GLOBAL); |
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| 396 | Tcl_DecrRefCount(command); |
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| 397 | command = NULL; |
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| 398 | |
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| 399 | if ((res != TCL_OK) && (interp != NULL) && (dataPtr->interp != interp) |
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| 400 | && (preserve == P_NO_PRESERVE)) { |
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| 401 | Tcl_SetObjResult(interp, Tcl_GetObjResult(dataPtr->interp)); |
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| 402 | return res; |
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| 403 | } |
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| 404 | |
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| 405 | /* |
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| 406 | * Step 3, transmit a possible conversion result to the underlying |
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| 407 | * channel, or ourselves. |
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| 408 | */ |
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| 409 | |
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| 410 | switch (transmit) { |
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| 411 | case TRANSMIT_DONT: |
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| 412 | /* nothing to do */ |
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| 413 | break; |
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| 414 | |
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| 415 | case TRANSMIT_DOWN: |
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| 416 | resObj = Tcl_GetObjResult(dataPtr->interp); |
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| 417 | resBuf = Tcl_GetByteArrayFromObj(resObj, &resLen); |
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| 418 | Tcl_WriteRaw(Tcl_GetStackedChannel(dataPtr->self), (char *) resBuf, |
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| 419 | resLen); |
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| 420 | break; |
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| 421 | |
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| 422 | case TRANSMIT_SELF: |
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| 423 | resObj = Tcl_GetObjResult(dataPtr->interp); |
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| 424 | resBuf = Tcl_GetByteArrayFromObj(resObj, &resLen); |
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| 425 | Tcl_WriteRaw(dataPtr->self, (char *) resBuf, resLen); |
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| 426 | break; |
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| 427 | |
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| 428 | case TRANSMIT_IBUF: |
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| 429 | resObj = Tcl_GetObjResult(dataPtr->interp); |
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| 430 | resBuf = Tcl_GetByteArrayFromObj(resObj, &resLen); |
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| 431 | ResultAdd(&dataPtr->result, resBuf, resLen); |
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| 432 | break; |
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| 433 | |
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| 434 | case TRANSMIT_NUM: |
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| 435 | /* |
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| 436 | * Interpret result as integer number. |
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| 437 | */ |
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| 438 | |
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| 439 | resObj = Tcl_GetObjResult(dataPtr->interp); |
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| 440 | TclGetIntFromObj(dataPtr->interp, resObj, &dataPtr->maxRead); |
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| 441 | break; |
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| 442 | } |
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| 443 | |
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| 444 | Tcl_ResetResult(dataPtr->interp); |
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| 445 | if (preserve == P_PRESERVE) { |
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| 446 | (void) Tcl_RestoreInterpState(dataPtr->interp, state); |
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| 447 | } |
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| 448 | return res; |
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| 449 | |
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| 450 | cleanup: |
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| 451 | if (preserve == P_PRESERVE) { |
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| 452 | (void) Tcl_RestoreInterpState(dataPtr->interp, state); |
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| 453 | } |
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| 454 | if (command != NULL) { |
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| 455 | Tcl_DecrRefCount(command); |
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| 456 | } |
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| 457 | return res; |
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| 458 | } |
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| 459 | |
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| 460 | /* |
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| 461 | *---------------------------------------------------------------------- |
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| 462 | * |
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| 463 | * TransformBlockModeProc -- |
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| 464 | * |
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| 465 | * Trap handler. Called by the generic IO system during option processing |
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| 466 | * to change the blocking mode of the channel. |
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| 467 | * |
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| 468 | * Side effects: |
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| 469 | * Forwards the request to the underlying channel. |
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| 470 | * |
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| 471 | * Result: |
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| 472 | * 0 if successful, errno when failed. |
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| 473 | * |
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| 474 | *---------------------------------------------------------------------- |
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| 475 | */ |
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| 476 | |
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| 477 | static int |
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| 478 | TransformBlockModeProc( |
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| 479 | ClientData instanceData, /* State of transformation. */ |
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| 480 | int mode) /* New blocking mode. */ |
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| 481 | { |
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| 482 | TransformChannelData *dataPtr = instanceData; |
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| 483 | |
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| 484 | if (mode == TCL_MODE_NONBLOCKING) { |
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| 485 | dataPtr->flags |= CHANNEL_ASYNC; |
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| 486 | } else { |
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| 487 | dataPtr->flags &= ~CHANNEL_ASYNC; |
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| 488 | } |
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| 489 | return 0; |
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| 490 | } |
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| 491 | |
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| 492 | /* |
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| 493 | *---------------------------------------------------------------------- |
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| 494 | * |
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| 495 | * TransformCloseProc -- |
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| 496 | * |
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| 497 | * Trap handler. Called by the generic IO system during destruction of |
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| 498 | * the transformation channel. |
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| 499 | * |
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| 500 | * Side effects: |
---|
| 501 | * Releases the memory allocated in 'Tcl_TransformObjCmd'. |
---|
| 502 | * |
---|
| 503 | * Result: |
---|
| 504 | * None. |
---|
| 505 | * |
---|
| 506 | *---------------------------------------------------------------------- |
---|
| 507 | */ |
---|
| 508 | |
---|
| 509 | static int |
---|
| 510 | TransformCloseProc( |
---|
| 511 | ClientData instanceData, |
---|
| 512 | Tcl_Interp *interp) |
---|
| 513 | { |
---|
| 514 | TransformChannelData *dataPtr = instanceData; |
---|
| 515 | |
---|
| 516 | /* |
---|
| 517 | * Important: In this procedure 'dataPtr->self' already points to the |
---|
| 518 | * underlying channel. |
---|
| 519 | * |
---|
| 520 | * There is no need to cancel an existing channel handler, this is already |
---|
| 521 | * done. Either by 'Tcl_UnstackChannel' or by the general cleanup in |
---|
| 522 | * 'Tcl_Close'. |
---|
| 523 | * |
---|
| 524 | * But we have to cancel an active timer to prevent it from firing on the |
---|
| 525 | * removed channel. |
---|
| 526 | */ |
---|
| 527 | |
---|
| 528 | if (dataPtr->timer != NULL) { |
---|
| 529 | Tcl_DeleteTimerHandler(dataPtr->timer); |
---|
| 530 | dataPtr->timer = NULL; |
---|
| 531 | } |
---|
| 532 | |
---|
| 533 | /* |
---|
| 534 | * Now flush data waiting in internal buffers to output and input. The |
---|
| 535 | * input must be done despite the fact that there is no real receiver for |
---|
| 536 | * it anymore. But the scripts might have sideeffects other parts of the |
---|
| 537 | * system rely on (f.e. signaling the close to interested parties). |
---|
| 538 | */ |
---|
| 539 | |
---|
| 540 | if (dataPtr->mode & TCL_WRITABLE) { |
---|
| 541 | ExecuteCallback(dataPtr, interp, A_FLUSH_WRITE, NULL, 0, |
---|
| 542 | TRANSMIT_DOWN, P_PRESERVE); |
---|
| 543 | } |
---|
| 544 | |
---|
| 545 | if ((dataPtr->mode & TCL_READABLE) && !dataPtr->readIsFlushed) { |
---|
| 546 | dataPtr->readIsFlushed = 1; |
---|
| 547 | ExecuteCallback(dataPtr, interp, A_FLUSH_READ, NULL, 0, TRANSMIT_IBUF, |
---|
| 548 | P_PRESERVE); |
---|
| 549 | } |
---|
| 550 | |
---|
| 551 | if (dataPtr->mode & TCL_WRITABLE) { |
---|
| 552 | ExecuteCallback(dataPtr, interp, A_DELETE_WRITE, NULL, 0, |
---|
| 553 | TRANSMIT_DONT, P_PRESERVE); |
---|
| 554 | } |
---|
| 555 | if (dataPtr->mode & TCL_READABLE) { |
---|
| 556 | ExecuteCallback(dataPtr, interp, A_DELETE_READ, NULL, 0, |
---|
| 557 | TRANSMIT_DONT, P_PRESERVE); |
---|
| 558 | } |
---|
| 559 | |
---|
| 560 | /* |
---|
| 561 | * General cleanup. |
---|
| 562 | */ |
---|
| 563 | |
---|
| 564 | ResultClear(&dataPtr->result); |
---|
| 565 | Tcl_DecrRefCount(dataPtr->command); |
---|
| 566 | ckfree((char *) dataPtr); |
---|
| 567 | return TCL_OK; |
---|
| 568 | } |
---|
| 569 | |
---|
| 570 | /* |
---|
| 571 | *---------------------------------------------------------------------- |
---|
| 572 | * |
---|
| 573 | * TransformInputProc -- |
---|
| 574 | * |
---|
| 575 | * Called by the generic IO system to convert read data. |
---|
| 576 | * |
---|
| 577 | * Side effects: |
---|
| 578 | * As defined by the conversion. |
---|
| 579 | * |
---|
| 580 | * Result: |
---|
| 581 | * A transformed buffer. |
---|
| 582 | * |
---|
| 583 | *---------------------------------------------------------------------- |
---|
| 584 | */ |
---|
| 585 | |
---|
| 586 | static int |
---|
| 587 | TransformInputProc( |
---|
| 588 | ClientData instanceData, |
---|
| 589 | char *buf, |
---|
| 590 | int toRead, |
---|
| 591 | int *errorCodePtr) |
---|
| 592 | { |
---|
| 593 | TransformChannelData *dataPtr = instanceData; |
---|
| 594 | int gotBytes, read, copied; |
---|
| 595 | Tcl_Channel downChan; |
---|
| 596 | |
---|
| 597 | /* |
---|
| 598 | * Should assert(dataPtr->mode & TCL_READABLE); |
---|
| 599 | */ |
---|
| 600 | |
---|
| 601 | if (toRead == 0) { |
---|
| 602 | /* |
---|
| 603 | * Catch a no-op. |
---|
| 604 | */ |
---|
| 605 | return 0; |
---|
| 606 | } |
---|
| 607 | |
---|
| 608 | gotBytes = 0; |
---|
| 609 | downChan = Tcl_GetStackedChannel(dataPtr->self); |
---|
| 610 | |
---|
| 611 | while (toRead > 0) { |
---|
| 612 | /* |
---|
| 613 | * Loop until the request is satisfied (or no data is available from |
---|
| 614 | * below, possibly EOF). |
---|
| 615 | */ |
---|
| 616 | |
---|
| 617 | copied = ResultCopy(&dataPtr->result, UCHARP(buf), toRead); |
---|
| 618 | toRead -= copied; |
---|
| 619 | buf += copied; |
---|
| 620 | gotBytes += copied; |
---|
| 621 | |
---|
| 622 | if (toRead == 0) { |
---|
| 623 | /* |
---|
| 624 | * The request was completely satisfied from our buffers. We can |
---|
| 625 | * break out of the loop and return to the caller. |
---|
| 626 | */ |
---|
| 627 | |
---|
| 628 | return gotBytes; |
---|
| 629 | } |
---|
| 630 | |
---|
| 631 | /* |
---|
| 632 | * Length (dataPtr->result) == 0, toRead > 0 here. Use the incoming |
---|
| 633 | * 'buf'! as target to store the intermediary information read from |
---|
| 634 | * the underlying channel. |
---|
| 635 | * |
---|
| 636 | * Ask the tcl level how much data it allows us to read from the |
---|
| 637 | * underlying channel. This feature allows the transform to signal EOF |
---|
| 638 | * upstream although there is none downstream. Useful to control an |
---|
| 639 | * unbounded 'fcopy', either through counting bytes, or by pattern |
---|
| 640 | * matching. |
---|
| 641 | */ |
---|
| 642 | |
---|
| 643 | ExecuteCallback(dataPtr, NULL, A_QUERY_MAXREAD, NULL, 0, |
---|
| 644 | TRANSMIT_NUM /* -> maxRead */, P_PRESERVE); |
---|
| 645 | |
---|
| 646 | if (dataPtr->maxRead >= 0) { |
---|
| 647 | if (dataPtr->maxRead < toRead) { |
---|
| 648 | toRead = dataPtr->maxRead; |
---|
| 649 | } |
---|
| 650 | } /* else: 'maxRead < 0' == Accept the current value of toRead. */ |
---|
| 651 | if (toRead <= 0) { |
---|
| 652 | return gotBytes; |
---|
| 653 | } |
---|
| 654 | |
---|
| 655 | /* |
---|
| 656 | * Get bytes from the underlying channel. |
---|
| 657 | */ |
---|
| 658 | |
---|
| 659 | read = Tcl_ReadRaw(downChan, buf, toRead); |
---|
| 660 | if (read < 0) { |
---|
| 661 | /* |
---|
| 662 | * Report errors to caller. EAGAIN is a special situation. If we |
---|
| 663 | * had some data before we report that instead of the request to |
---|
| 664 | * re-try. |
---|
| 665 | */ |
---|
| 666 | |
---|
| 667 | if ((Tcl_GetErrno() == EAGAIN) && (gotBytes > 0)) { |
---|
| 668 | return gotBytes; |
---|
| 669 | } |
---|
| 670 | |
---|
| 671 | *errorCodePtr = Tcl_GetErrno(); |
---|
| 672 | return -1; |
---|
| 673 | } else if (read == 0) { |
---|
| 674 | /* |
---|
| 675 | * Check wether we hit on EOF in the underlying channel or not. If |
---|
| 676 | * not differentiate between blocking and non-blocking modes. In |
---|
| 677 | * non-blocking mode we ran temporarily out of data. Signal this |
---|
| 678 | * to the caller via EWOULDBLOCK and error return (-1). In the |
---|
| 679 | * other cases we simply return what we got and let the caller |
---|
| 680 | * wait for more. On the other hand, if we got an EOF we have to |
---|
| 681 | * convert and flush all waiting partial data. |
---|
| 682 | */ |
---|
| 683 | |
---|
| 684 | if (!Tcl_Eof(downChan)) { |
---|
| 685 | if ((gotBytes == 0) && (dataPtr->flags & CHANNEL_ASYNC)) { |
---|
| 686 | *errorCodePtr = EWOULDBLOCK; |
---|
| 687 | return -1; |
---|
| 688 | } |
---|
| 689 | return gotBytes; |
---|
| 690 | } |
---|
| 691 | |
---|
| 692 | if (dataPtr->readIsFlushed) { |
---|
| 693 | /* |
---|
| 694 | * Already flushed, nothing to do anymore. |
---|
| 695 | */ |
---|
| 696 | |
---|
| 697 | return gotBytes; |
---|
| 698 | } |
---|
| 699 | |
---|
| 700 | dataPtr->readIsFlushed = 1; |
---|
| 701 | ExecuteCallback(dataPtr, NULL, A_FLUSH_READ, NULL, 0, |
---|
| 702 | TRANSMIT_IBUF, P_PRESERVE); |
---|
| 703 | |
---|
| 704 | if (ResultEmpty(&dataPtr->result)) { |
---|
| 705 | /* |
---|
| 706 | * We had nothing to flush. |
---|
| 707 | */ |
---|
| 708 | |
---|
| 709 | return gotBytes; |
---|
| 710 | } |
---|
| 711 | |
---|
| 712 | continue; /* at: while (toRead > 0) */ |
---|
| 713 | } /* read == 0 */ |
---|
| 714 | |
---|
| 715 | /* |
---|
| 716 | * Transform the read chunk and add the result to our read buffer |
---|
| 717 | * (dataPtr->result). |
---|
| 718 | */ |
---|
| 719 | |
---|
| 720 | if (ExecuteCallback(dataPtr, NULL, A_READ, UCHARP(buf), read, |
---|
| 721 | TRANSMIT_IBUF, P_PRESERVE) != TCL_OK) { |
---|
| 722 | *errorCodePtr = EINVAL; |
---|
| 723 | return -1; |
---|
| 724 | } |
---|
| 725 | } /* while toRead > 0 */ |
---|
| 726 | |
---|
| 727 | return gotBytes; |
---|
| 728 | } |
---|
| 729 | |
---|
| 730 | /* |
---|
| 731 | *---------------------------------------------------------------------- |
---|
| 732 | * |
---|
| 733 | * TransformOutputProc -- |
---|
| 734 | * |
---|
| 735 | * Called by the generic IO system to convert data waiting to be written. |
---|
| 736 | * |
---|
| 737 | * Side effects: |
---|
| 738 | * As defined by the transformation. |
---|
| 739 | * |
---|
| 740 | * Result: |
---|
| 741 | * A transformed buffer. |
---|
| 742 | * |
---|
| 743 | *---------------------------------------------------------------------- |
---|
| 744 | */ |
---|
| 745 | |
---|
| 746 | static int |
---|
| 747 | TransformOutputProc( |
---|
| 748 | ClientData instanceData, |
---|
| 749 | const char *buf, |
---|
| 750 | int toWrite, |
---|
| 751 | int *errorCodePtr) |
---|
| 752 | { |
---|
| 753 | TransformChannelData *dataPtr = instanceData; |
---|
| 754 | |
---|
| 755 | /* |
---|
| 756 | * Should assert(dataPtr->mode & TCL_WRITABLE); |
---|
| 757 | */ |
---|
| 758 | |
---|
| 759 | if (toWrite == 0) { |
---|
| 760 | /* |
---|
| 761 | * Catch a no-op. |
---|
| 762 | */ |
---|
| 763 | |
---|
| 764 | return 0; |
---|
| 765 | } |
---|
| 766 | |
---|
| 767 | if (ExecuteCallback(dataPtr, NULL, A_WRITE, UCHARP(buf), toWrite, |
---|
| 768 | TRANSMIT_DOWN, P_NO_PRESERVE) != TCL_OK) { |
---|
| 769 | *errorCodePtr = EINVAL; |
---|
| 770 | return -1; |
---|
| 771 | } |
---|
| 772 | |
---|
| 773 | return toWrite; |
---|
| 774 | } |
---|
| 775 | |
---|
| 776 | /* |
---|
| 777 | *---------------------------------------------------------------------- |
---|
| 778 | * |
---|
| 779 | * TransformSeekProc -- |
---|
| 780 | * |
---|
| 781 | * This procedure is called by the generic IO level to move the access |
---|
| 782 | * point in a channel. |
---|
| 783 | * |
---|
| 784 | * Side effects: |
---|
| 785 | * Moves the location at which the channel will be accessed in future |
---|
| 786 | * operations. Flushes all transformation buffers, then forwards it to |
---|
| 787 | * the underlying channel. |
---|
| 788 | * |
---|
| 789 | * Result: |
---|
| 790 | * -1 if failed, the new position if successful. An output argument |
---|
| 791 | * contains the POSIX error code if an error occurred, or zero. |
---|
| 792 | * |
---|
| 793 | *---------------------------------------------------------------------- |
---|
| 794 | */ |
---|
| 795 | |
---|
| 796 | static int |
---|
| 797 | TransformSeekProc( |
---|
| 798 | ClientData instanceData, /* The channel to manipulate. */ |
---|
| 799 | long offset, /* Size of movement. */ |
---|
| 800 | int mode, /* How to move. */ |
---|
| 801 | int *errorCodePtr) /* Location of error flag. */ |
---|
| 802 | { |
---|
| 803 | TransformChannelData *dataPtr = instanceData; |
---|
| 804 | Tcl_Channel parent = Tcl_GetStackedChannel(dataPtr->self); |
---|
| 805 | Tcl_ChannelType *parentType = Tcl_GetChannelType(parent); |
---|
| 806 | Tcl_DriverSeekProc *parentSeekProc = Tcl_ChannelSeekProc(parentType); |
---|
| 807 | |
---|
| 808 | if ((offset == 0) && (mode == SEEK_CUR)) { |
---|
| 809 | /* |
---|
| 810 | * This is no seek but a request to tell the caller the current |
---|
| 811 | * location. Simply pass the request down. |
---|
| 812 | */ |
---|
| 813 | |
---|
| 814 | return parentSeekProc(Tcl_GetChannelInstanceData(parent), offset, |
---|
| 815 | mode, errorCodePtr); |
---|
| 816 | } |
---|
| 817 | |
---|
| 818 | /* |
---|
| 819 | * It is a real request to change the position. Flush all data waiting for |
---|
| 820 | * output and discard everything in the input buffers. Then pass the |
---|
| 821 | * request down, unchanged. |
---|
| 822 | */ |
---|
| 823 | |
---|
| 824 | if (dataPtr->mode & TCL_WRITABLE) { |
---|
| 825 | ExecuteCallback(dataPtr, NULL, A_FLUSH_WRITE, NULL, 0, TRANSMIT_DOWN, |
---|
| 826 | P_NO_PRESERVE); |
---|
| 827 | } |
---|
| 828 | |
---|
| 829 | if (dataPtr->mode & TCL_READABLE) { |
---|
| 830 | ExecuteCallback(dataPtr, NULL, A_CLEAR_READ, NULL, 0, TRANSMIT_DONT, |
---|
| 831 | P_NO_PRESERVE); |
---|
| 832 | ResultClear(&dataPtr->result); |
---|
| 833 | dataPtr->readIsFlushed = 0; |
---|
| 834 | } |
---|
| 835 | |
---|
| 836 | return parentSeekProc(Tcl_GetChannelInstanceData(parent), offset, mode, |
---|
| 837 | errorCodePtr); |
---|
| 838 | } |
---|
| 839 | |
---|
| 840 | /* |
---|
| 841 | *---------------------------------------------------------------------- |
---|
| 842 | * |
---|
| 843 | * TransformWideSeekProc -- |
---|
| 844 | * |
---|
| 845 | * This procedure is called by the generic IO level to move the access |
---|
| 846 | * point in a channel, with a (potentially) 64-bit offset. |
---|
| 847 | * |
---|
| 848 | * Side effects: |
---|
| 849 | * Moves the location at which the channel will be accessed in future |
---|
| 850 | * operations. Flushes all transformation buffers, then forwards it to |
---|
| 851 | * the underlying channel. |
---|
| 852 | * |
---|
| 853 | * Result: |
---|
| 854 | * -1 if failed, the new position if successful. An output argument |
---|
| 855 | * contains the POSIX error code if an error occurred, or zero. |
---|
| 856 | * |
---|
| 857 | *---------------------------------------------------------------------- |
---|
| 858 | */ |
---|
| 859 | |
---|
| 860 | static Tcl_WideInt |
---|
| 861 | TransformWideSeekProc( |
---|
| 862 | ClientData instanceData, /* The channel to manipulate. */ |
---|
| 863 | Tcl_WideInt offset, /* Size of movement. */ |
---|
| 864 | int mode, /* How to move. */ |
---|
| 865 | int *errorCodePtr) /* Location of error flag. */ |
---|
| 866 | { |
---|
| 867 | TransformChannelData *dataPtr = instanceData; |
---|
| 868 | Tcl_Channel parent = Tcl_GetStackedChannel(dataPtr->self); |
---|
| 869 | Tcl_ChannelType *parentType = Tcl_GetChannelType(parent); |
---|
| 870 | Tcl_DriverSeekProc *parentSeekProc = Tcl_ChannelSeekProc(parentType); |
---|
| 871 | Tcl_DriverWideSeekProc *parentWideSeekProc = |
---|
| 872 | Tcl_ChannelWideSeekProc(parentType); |
---|
| 873 | ClientData parentData = Tcl_GetChannelInstanceData(parent); |
---|
| 874 | |
---|
| 875 | if ((offset == Tcl_LongAsWide(0)) && (mode == SEEK_CUR)) { |
---|
| 876 | /* |
---|
| 877 | * This is no seek but a request to tell the caller the current |
---|
| 878 | * location. Simply pass the request down. |
---|
| 879 | */ |
---|
| 880 | |
---|
| 881 | if (parentWideSeekProc != NULL) { |
---|
| 882 | return parentWideSeekProc(parentData, offset, mode, errorCodePtr); |
---|
| 883 | } |
---|
| 884 | |
---|
| 885 | return Tcl_LongAsWide(parentSeekProc(parentData, 0, mode, |
---|
| 886 | errorCodePtr)); |
---|
| 887 | } |
---|
| 888 | |
---|
| 889 | /* |
---|
| 890 | * It is a real request to change the position. Flush all data waiting for |
---|
| 891 | * output and discard everything in the input buffers. Then pass the |
---|
| 892 | * request down, unchanged. |
---|
| 893 | */ |
---|
| 894 | |
---|
| 895 | if (dataPtr->mode & TCL_WRITABLE) { |
---|
| 896 | ExecuteCallback(dataPtr, NULL, A_FLUSH_WRITE, NULL, 0, TRANSMIT_DOWN, |
---|
| 897 | P_NO_PRESERVE); |
---|
| 898 | } |
---|
| 899 | |
---|
| 900 | if (dataPtr->mode & TCL_READABLE) { |
---|
| 901 | ExecuteCallback(dataPtr, NULL, A_CLEAR_READ, NULL, 0, TRANSMIT_DONT, |
---|
| 902 | P_NO_PRESERVE); |
---|
| 903 | ResultClear(&dataPtr->result); |
---|
| 904 | dataPtr->readIsFlushed = 0; |
---|
| 905 | } |
---|
| 906 | |
---|
| 907 | /* |
---|
| 908 | * If we have a wide seek capability, we should stick with that. |
---|
| 909 | */ |
---|
| 910 | |
---|
| 911 | if (parentWideSeekProc != NULL) { |
---|
| 912 | return parentWideSeekProc(parentData, offset, mode, errorCodePtr); |
---|
| 913 | } |
---|
| 914 | |
---|
| 915 | /* |
---|
| 916 | * We're transferring to narrow seeks at this point; this is a bit complex |
---|
| 917 | * because we have to check whether the seek is possible first (i.e. |
---|
| 918 | * whether we are losing information in truncating the bits of the |
---|
| 919 | * offset). Luckily, there's a defined error for what happens when trying |
---|
| 920 | * to go out of the representable range. |
---|
| 921 | */ |
---|
| 922 | |
---|
| 923 | if (offset<Tcl_LongAsWide(LONG_MIN) || offset>Tcl_LongAsWide(LONG_MAX)) { |
---|
| 924 | *errorCodePtr = EOVERFLOW; |
---|
| 925 | return Tcl_LongAsWide(-1); |
---|
| 926 | } |
---|
| 927 | |
---|
| 928 | return Tcl_LongAsWide(parentSeekProc(parentData, Tcl_WideAsLong(offset), |
---|
| 929 | mode, errorCodePtr)); |
---|
| 930 | } |
---|
| 931 | |
---|
| 932 | /* |
---|
| 933 | *---------------------------------------------------------------------- |
---|
| 934 | * |
---|
| 935 | * TransformSetOptionProc -- |
---|
| 936 | * |
---|
| 937 | * Called by generic layer to handle the reconfiguration of channel |
---|
| 938 | * specific options. As this channel type does not have such, it simply |
---|
| 939 | * passes all requests downstream. |
---|
| 940 | * |
---|
| 941 | * Side effects: |
---|
| 942 | * As defined by the channel downstream. |
---|
| 943 | * |
---|
| 944 | * Result: |
---|
| 945 | * A standard TCL error code. |
---|
| 946 | * |
---|
| 947 | *---------------------------------------------------------------------- |
---|
| 948 | */ |
---|
| 949 | |
---|
| 950 | static int |
---|
| 951 | TransformSetOptionProc( |
---|
| 952 | ClientData instanceData, |
---|
| 953 | Tcl_Interp *interp, |
---|
| 954 | const char *optionName, |
---|
| 955 | const char *value) |
---|
| 956 | { |
---|
| 957 | TransformChannelData *dataPtr = instanceData; |
---|
| 958 | Tcl_Channel downChan = Tcl_GetStackedChannel(dataPtr->self); |
---|
| 959 | Tcl_DriverSetOptionProc *setOptionProc; |
---|
| 960 | |
---|
| 961 | setOptionProc = Tcl_ChannelSetOptionProc(Tcl_GetChannelType(downChan)); |
---|
| 962 | if (setOptionProc == NULL) { |
---|
| 963 | return TCL_ERROR; |
---|
| 964 | } |
---|
| 965 | |
---|
| 966 | return setOptionProc(Tcl_GetChannelInstanceData(downChan), interp, |
---|
| 967 | optionName, value); |
---|
| 968 | } |
---|
| 969 | |
---|
| 970 | /* |
---|
| 971 | *---------------------------------------------------------------------- |
---|
| 972 | * |
---|
| 973 | * TransformGetOptionProc -- |
---|
| 974 | * |
---|
| 975 | * Called by generic layer to handle requests for the values of channel |
---|
| 976 | * specific options. As this channel type does not have such, it simply |
---|
| 977 | * passes all requests downstream. |
---|
| 978 | * |
---|
| 979 | * Side effects: |
---|
| 980 | * As defined by the channel downstream. |
---|
| 981 | * |
---|
| 982 | * Result: |
---|
| 983 | * A standard TCL error code. |
---|
| 984 | * |
---|
| 985 | *---------------------------------------------------------------------- |
---|
| 986 | */ |
---|
| 987 | |
---|
| 988 | static int |
---|
| 989 | TransformGetOptionProc( |
---|
| 990 | ClientData instanceData, |
---|
| 991 | Tcl_Interp *interp, |
---|
| 992 | const char *optionName, |
---|
| 993 | Tcl_DString *dsPtr) |
---|
| 994 | { |
---|
| 995 | TransformChannelData *dataPtr = instanceData; |
---|
| 996 | Tcl_Channel downChan = Tcl_GetStackedChannel(dataPtr->self); |
---|
| 997 | Tcl_DriverGetOptionProc *getOptionProc; |
---|
| 998 | |
---|
| 999 | getOptionProc = Tcl_ChannelGetOptionProc(Tcl_GetChannelType(downChan)); |
---|
| 1000 | if (getOptionProc != NULL) { |
---|
| 1001 | return getOptionProc(Tcl_GetChannelInstanceData(downChan), interp, |
---|
| 1002 | optionName, dsPtr); |
---|
| 1003 | } else if (optionName == NULL) { |
---|
| 1004 | /* |
---|
| 1005 | * Request is query for all options, this is ok. |
---|
| 1006 | */ |
---|
| 1007 | |
---|
| 1008 | return TCL_OK; |
---|
| 1009 | } |
---|
| 1010 | |
---|
| 1011 | /* |
---|
| 1012 | * Request for a specific option has to fail, since we don't have any. |
---|
| 1013 | */ |
---|
| 1014 | |
---|
| 1015 | return TCL_ERROR; |
---|
| 1016 | } |
---|
| 1017 | |
---|
| 1018 | /* |
---|
| 1019 | *---------------------------------------------------------------------- |
---|
| 1020 | * |
---|
| 1021 | * TransformWatchProc -- |
---|
| 1022 | * |
---|
| 1023 | * Initialize the notifier to watch for events from this channel. |
---|
| 1024 | * |
---|
| 1025 | * Side effects: |
---|
| 1026 | * Sets up the notifier so that a future event on the channel will be |
---|
| 1027 | * seen by Tcl. |
---|
| 1028 | * |
---|
| 1029 | * Result: |
---|
| 1030 | * None. |
---|
| 1031 | * |
---|
| 1032 | *---------------------------------------------------------------------- |
---|
| 1033 | */ |
---|
| 1034 | |
---|
| 1035 | /* ARGSUSED */ |
---|
| 1036 | static void |
---|
| 1037 | TransformWatchProc( |
---|
| 1038 | ClientData instanceData, /* Channel to watch. */ |
---|
| 1039 | int mask) /* Events of interest. */ |
---|
| 1040 | { |
---|
| 1041 | TransformChannelData *dataPtr = instanceData; |
---|
| 1042 | Tcl_Channel downChan; |
---|
| 1043 | |
---|
| 1044 | /* |
---|
| 1045 | * The caller expressed interest in events occuring for this channel. We |
---|
| 1046 | * are forwarding the call to the underlying channel now. |
---|
| 1047 | */ |
---|
| 1048 | |
---|
| 1049 | dataPtr->watchMask = mask; |
---|
| 1050 | |
---|
| 1051 | /* |
---|
| 1052 | * No channel handlers any more. We will be notified automatically about |
---|
| 1053 | * events on the channel below via a call to our 'TransformNotifyProc'. |
---|
| 1054 | * But we have to pass the interest down now. We are allowed to add |
---|
| 1055 | * additional 'interest' to the mask if we want to. But this |
---|
| 1056 | * transformation has no such interest. It just passes the request down, |
---|
| 1057 | * unchanged. |
---|
| 1058 | */ |
---|
| 1059 | |
---|
| 1060 | downChan = Tcl_GetStackedChannel(dataPtr->self); |
---|
| 1061 | |
---|
| 1062 | Tcl_GetChannelType(downChan)->watchProc( |
---|
| 1063 | Tcl_GetChannelInstanceData(downChan), mask); |
---|
| 1064 | |
---|
| 1065 | /* |
---|
| 1066 | * Management of the internal timer. |
---|
| 1067 | */ |
---|
| 1068 | |
---|
| 1069 | if ((dataPtr->timer != NULL) && |
---|
| 1070 | (!(mask & TCL_READABLE) || ResultEmpty(&dataPtr->result))) { |
---|
| 1071 | /* |
---|
| 1072 | * A pending timer exists, but either is there no (more) interest in |
---|
| 1073 | * the events it generates or nothing is available for reading, so |
---|
| 1074 | * remove it. |
---|
| 1075 | */ |
---|
| 1076 | |
---|
| 1077 | Tcl_DeleteTimerHandler(dataPtr->timer); |
---|
| 1078 | dataPtr->timer = NULL; |
---|
| 1079 | } |
---|
| 1080 | |
---|
| 1081 | if ((dataPtr->timer == NULL) && (mask & TCL_READABLE) |
---|
| 1082 | && !ResultEmpty(&dataPtr->result)) { |
---|
| 1083 | /* |
---|
| 1084 | * There is no pending timer, but there is interest in readable events |
---|
| 1085 | * and we actually have data waiting, so generate a timer to flush |
---|
| 1086 | * that. |
---|
| 1087 | */ |
---|
| 1088 | |
---|
| 1089 | dataPtr->timer = Tcl_CreateTimerHandler(FLUSH_DELAY, |
---|
| 1090 | TransformChannelHandlerTimer, dataPtr); |
---|
| 1091 | } |
---|
| 1092 | } |
---|
| 1093 | |
---|
| 1094 | /* |
---|
| 1095 | *---------------------------------------------------------------------- |
---|
| 1096 | * |
---|
| 1097 | * TransformGetFileHandleProc -- |
---|
| 1098 | * |
---|
| 1099 | * Called from Tcl_GetChannelHandle to retrieve OS specific file handle |
---|
| 1100 | * from inside this channel. |
---|
| 1101 | * |
---|
| 1102 | * Side effects: |
---|
| 1103 | * None. |
---|
| 1104 | * |
---|
| 1105 | * Result: |
---|
| 1106 | * The appropriate Tcl_File or NULL if not present. |
---|
| 1107 | * |
---|
| 1108 | *---------------------------------------------------------------------- |
---|
| 1109 | */ |
---|
| 1110 | |
---|
| 1111 | static int |
---|
| 1112 | TransformGetFileHandleProc( |
---|
| 1113 | ClientData instanceData, /* Channel to query. */ |
---|
| 1114 | int direction, /* Direction of interest. */ |
---|
| 1115 | ClientData *handlePtr) /* Place to store the handle into. */ |
---|
| 1116 | { |
---|
| 1117 | TransformChannelData *dataPtr = instanceData; |
---|
| 1118 | |
---|
| 1119 | /* |
---|
| 1120 | * Return the handle belonging to parent channel. IOW, pass the request |
---|
| 1121 | * down and the result up. |
---|
| 1122 | */ |
---|
| 1123 | |
---|
| 1124 | return Tcl_GetChannelHandle(Tcl_GetStackedChannel(dataPtr->self), |
---|
| 1125 | direction, handlePtr); |
---|
| 1126 | } |
---|
| 1127 | |
---|
| 1128 | /* |
---|
| 1129 | *---------------------------------------------------------------------- |
---|
| 1130 | * |
---|
| 1131 | * TransformNotifyProc -- |
---|
| 1132 | * |
---|
| 1133 | * Handler called by Tcl to inform us of activity on the underlying |
---|
| 1134 | * channel. |
---|
| 1135 | * |
---|
| 1136 | * Side effects: |
---|
| 1137 | * May process the incoming event by itself. |
---|
| 1138 | * |
---|
| 1139 | * Result: |
---|
| 1140 | * None. |
---|
| 1141 | * |
---|
| 1142 | *---------------------------------------------------------------------- |
---|
| 1143 | */ |
---|
| 1144 | |
---|
| 1145 | static int |
---|
| 1146 | TransformNotifyProc( |
---|
| 1147 | ClientData clientData, /* The state of the notified |
---|
| 1148 | * transformation. */ |
---|
| 1149 | int mask) /* The mask of occuring events. */ |
---|
| 1150 | { |
---|
| 1151 | TransformChannelData *dataPtr = clientData; |
---|
| 1152 | |
---|
| 1153 | /* |
---|
| 1154 | * An event occured in the underlying channel. This transformation doesn't |
---|
| 1155 | * process such events thus returns the incoming mask unchanged. |
---|
| 1156 | */ |
---|
| 1157 | |
---|
| 1158 | if (dataPtr->timer != NULL) { |
---|
| 1159 | /* |
---|
| 1160 | * Delete an existing timer. It was not fired, yet we are here, so the |
---|
| 1161 | * channel below generated such an event and we don't have to. The |
---|
| 1162 | * renewal of the interest after the execution of channel handlers |
---|
| 1163 | * will eventually cause us to recreate the timer (in |
---|
| 1164 | * TransformWatchProc). |
---|
| 1165 | */ |
---|
| 1166 | |
---|
| 1167 | Tcl_DeleteTimerHandler(dataPtr->timer); |
---|
| 1168 | dataPtr->timer = NULL; |
---|
| 1169 | } |
---|
| 1170 | return mask; |
---|
| 1171 | } |
---|
| 1172 | |
---|
| 1173 | /* |
---|
| 1174 | *---------------------------------------------------------------------- |
---|
| 1175 | * |
---|
| 1176 | * TransformChannelHandlerTimer -- |
---|
| 1177 | * |
---|
| 1178 | * Called by the notifier (-> timer) to flush out information waiting in |
---|
| 1179 | * the input buffer. |
---|
| 1180 | * |
---|
| 1181 | * Side effects: |
---|
| 1182 | * As of 'Tcl_NotifyChannel'. |
---|
| 1183 | * |
---|
| 1184 | * Result: |
---|
| 1185 | * None. |
---|
| 1186 | * |
---|
| 1187 | *---------------------------------------------------------------------- |
---|
| 1188 | */ |
---|
| 1189 | |
---|
| 1190 | static void |
---|
| 1191 | TransformChannelHandlerTimer( |
---|
| 1192 | ClientData clientData) /* Transformation to query. */ |
---|
| 1193 | { |
---|
| 1194 | TransformChannelData *dataPtr = clientData; |
---|
| 1195 | |
---|
| 1196 | dataPtr->timer = NULL; |
---|
| 1197 | if (!(dataPtr->watchMask&TCL_READABLE) || ResultEmpty(&dataPtr->result)) { |
---|
| 1198 | /* |
---|
| 1199 | * The timer fired, but either is there no (more) interest in the |
---|
| 1200 | * events it generates or nothing is available for reading, so ignore |
---|
| 1201 | * it and don't recreate it. |
---|
| 1202 | */ |
---|
| 1203 | |
---|
| 1204 | return; |
---|
| 1205 | } |
---|
| 1206 | Tcl_NotifyChannel(dataPtr->self, TCL_READABLE); |
---|
| 1207 | } |
---|
| 1208 | |
---|
| 1209 | /* |
---|
| 1210 | *---------------------------------------------------------------------- |
---|
| 1211 | * |
---|
| 1212 | * ResultClear -- |
---|
| 1213 | * |
---|
| 1214 | * Deallocates any memory allocated by 'ResultAdd'. |
---|
| 1215 | * |
---|
| 1216 | * Side effects: |
---|
| 1217 | * See above. |
---|
| 1218 | * |
---|
| 1219 | * Result: |
---|
| 1220 | * None. |
---|
| 1221 | * |
---|
| 1222 | *---------------------------------------------------------------------- |
---|
| 1223 | */ |
---|
| 1224 | |
---|
| 1225 | static inline void |
---|
| 1226 | ResultClear( |
---|
| 1227 | ResultBuffer *r) /* Reference to the buffer to clear out. */ |
---|
| 1228 | { |
---|
| 1229 | r->used = 0; |
---|
| 1230 | |
---|
| 1231 | if (r->allocated) { |
---|
| 1232 | ckfree((char *) r->buf); |
---|
| 1233 | r->buf = NULL; |
---|
| 1234 | r->allocated = 0; |
---|
| 1235 | } |
---|
| 1236 | } |
---|
| 1237 | |
---|
| 1238 | /* |
---|
| 1239 | *---------------------------------------------------------------------- |
---|
| 1240 | * |
---|
| 1241 | * ResultInit -- |
---|
| 1242 | * |
---|
| 1243 | * Initializes the specified buffer structure. The structure will contain |
---|
| 1244 | * valid information for an emtpy buffer. |
---|
| 1245 | * |
---|
| 1246 | * Side effects: |
---|
| 1247 | * See above. |
---|
| 1248 | * |
---|
| 1249 | * Result: |
---|
| 1250 | * None. |
---|
| 1251 | * |
---|
| 1252 | *---------------------------------------------------------------------- |
---|
| 1253 | */ |
---|
| 1254 | |
---|
| 1255 | static inline void |
---|
| 1256 | ResultInit( |
---|
| 1257 | ResultBuffer *r) /* Reference to the structure to |
---|
| 1258 | * initialize. */ |
---|
| 1259 | { |
---|
| 1260 | r->used = 0; |
---|
| 1261 | r->allocated = 0; |
---|
| 1262 | r->buf = NULL; |
---|
| 1263 | } |
---|
| 1264 | |
---|
| 1265 | /* |
---|
| 1266 | *---------------------------------------------------------------------- |
---|
| 1267 | * |
---|
| 1268 | * ResultEmpty -- |
---|
| 1269 | * |
---|
| 1270 | * Returns whether the number of bytes stored in the buffer is zero. |
---|
| 1271 | * |
---|
| 1272 | * Side effects: |
---|
| 1273 | * None. |
---|
| 1274 | * |
---|
| 1275 | * Result: |
---|
| 1276 | * A boolean. |
---|
| 1277 | * |
---|
| 1278 | *---------------------------------------------------------------------- |
---|
| 1279 | */ |
---|
| 1280 | |
---|
| 1281 | static inline int |
---|
| 1282 | ResultEmpty( |
---|
| 1283 | ResultBuffer *r) /* The structure to query. */ |
---|
| 1284 | { |
---|
| 1285 | return r->used == 0; |
---|
| 1286 | } |
---|
| 1287 | |
---|
| 1288 | /* |
---|
| 1289 | *---------------------------------------------------------------------- |
---|
| 1290 | * |
---|
| 1291 | * ResultCopy -- |
---|
| 1292 | * |
---|
| 1293 | * Copies the requested number of bytes from the buffer into the |
---|
| 1294 | * specified array and removes them from the buffer afterward. Copies |
---|
| 1295 | * less if there is not enough data in the buffer. |
---|
| 1296 | * |
---|
| 1297 | * Side effects: |
---|
| 1298 | * See above. |
---|
| 1299 | * |
---|
| 1300 | * Result: |
---|
| 1301 | * The number of actually copied bytes, possibly less than 'toRead'. |
---|
| 1302 | * |
---|
| 1303 | *---------------------------------------------------------------------- |
---|
| 1304 | */ |
---|
| 1305 | |
---|
| 1306 | static inline int |
---|
| 1307 | ResultCopy( |
---|
| 1308 | ResultBuffer *r, /* The buffer to read from. */ |
---|
| 1309 | unsigned char *buf, /* The buffer to copy into. */ |
---|
| 1310 | size_t toRead) /* Number of requested bytes. */ |
---|
| 1311 | { |
---|
| 1312 | if (r->used == 0) { |
---|
| 1313 | /* |
---|
| 1314 | * Nothing to copy in the case of an empty buffer. |
---|
| 1315 | */ |
---|
| 1316 | |
---|
| 1317 | return 0; |
---|
| 1318 | } else if (r->used == toRead) { |
---|
| 1319 | /* |
---|
| 1320 | * We have just enough. Copy everything to the caller. |
---|
| 1321 | */ |
---|
| 1322 | |
---|
| 1323 | memcpy(buf, r->buf, toRead); |
---|
| 1324 | r->used = 0; |
---|
| 1325 | } else if (r->used > toRead) { |
---|
| 1326 | /* |
---|
| 1327 | * The internal buffer contains more than requested. Copy the |
---|
| 1328 | * requested subset to the caller, and shift the remaining bytes down. |
---|
| 1329 | */ |
---|
| 1330 | |
---|
| 1331 | memcpy(buf, r->buf, toRead); |
---|
| 1332 | memmove(r->buf, r->buf + toRead, r->used - toRead); |
---|
| 1333 | r->used -= toRead; |
---|
| 1334 | } else { |
---|
| 1335 | /* |
---|
| 1336 | * There is not enough in the buffer to satisfy the caller, so take |
---|
| 1337 | * everything. |
---|
| 1338 | */ |
---|
| 1339 | |
---|
| 1340 | memcpy(buf, r->buf, r->used); |
---|
| 1341 | toRead = r->used; |
---|
| 1342 | r->used = 0; |
---|
| 1343 | } |
---|
| 1344 | return toRead; |
---|
| 1345 | } |
---|
| 1346 | |
---|
| 1347 | /* |
---|
| 1348 | *---------------------------------------------------------------------- |
---|
| 1349 | * |
---|
| 1350 | * ResultAdd -- |
---|
| 1351 | * |
---|
| 1352 | * Adds the bytes in the specified array to the buffer, by appending it. |
---|
| 1353 | * |
---|
| 1354 | * Side effects: |
---|
| 1355 | * See above. |
---|
| 1356 | * |
---|
| 1357 | * Result: |
---|
| 1358 | * None. |
---|
| 1359 | * |
---|
| 1360 | *---------------------------------------------------------------------- |
---|
| 1361 | */ |
---|
| 1362 | |
---|
| 1363 | static inline void |
---|
| 1364 | ResultAdd( |
---|
| 1365 | ResultBuffer *r, /* The buffer to extend. */ |
---|
| 1366 | unsigned char *buf, /* The buffer to read from. */ |
---|
| 1367 | size_t toWrite) /* The number of bytes in 'buf'. */ |
---|
| 1368 | { |
---|
| 1369 | if (r->used + toWrite > r->allocated) { |
---|
| 1370 | /* |
---|
| 1371 | * Extension of the internal buffer is required. |
---|
| 1372 | */ |
---|
| 1373 | |
---|
| 1374 | if (r->allocated == 0) { |
---|
| 1375 | r->allocated = toWrite + INCREMENT; |
---|
| 1376 | r->buf = UCHARP(ckalloc(r->allocated)); |
---|
| 1377 | } else { |
---|
| 1378 | r->allocated += toWrite + INCREMENT; |
---|
| 1379 | r->buf = UCHARP(ckrealloc((char *) r->buf, r->allocated)); |
---|
| 1380 | } |
---|
| 1381 | } |
---|
| 1382 | |
---|
| 1383 | /* |
---|
| 1384 | * Now we may copy the data. |
---|
| 1385 | */ |
---|
| 1386 | |
---|
| 1387 | memcpy(r->buf + r->used, buf, toWrite); |
---|
| 1388 | r->used += toWrite; |
---|
| 1389 | } |
---|
| 1390 | |
---|
| 1391 | /* |
---|
| 1392 | * Local Variables: |
---|
| 1393 | * mode: c |
---|
| 1394 | * c-basic-offset: 4 |
---|
| 1395 | * fill-column: 78 |
---|
| 1396 | * End: |
---|
| 1397 | */ |
---|