diff options
Diffstat (limited to 'generic/tclIO.c')
| -rw-r--r-- | generic/tclIO.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/generic/tclIO.c b/generic/tclIO.c index 40998cc..b16bdbb 100644 --- a/generic/tclIO.c +++ b/generic/tclIO.c @@ -16,6 +16,108 @@ #include <assert.h> /* + * For each channel handler registered in a call to Tcl_CreateChannelHandler, + * there is one record of the following type. All of records for a specific + * channel are chained together in a singly linked list which is stored in + * the channel structure. + */ + +typedef struct ChannelHandler { + Channel *chanPtr; /* The channel structure for this channel. */ + int mask; /* Mask of desired events. */ + Tcl_ChannelProc *proc; /* Procedure to call in the type of + * Tcl_CreateChannelHandler. */ + ClientData clientData; /* Argument to pass to procedure. */ + struct ChannelHandler *nextPtr; + /* Next one in list of registered handlers. */ +} ChannelHandler; + +/* + * This structure keeps track of the current ChannelHandler being invoked in + * the current invocation of ChannelHandlerEventProc. There is a potential + * problem if a ChannelHandler is deleted while it is the current one, since + * ChannelHandlerEventProc needs to look at the nextPtr field. To handle this + * problem, structures of the type below indicate the next handler to be + * processed for any (recursively nested) dispatches in progress. The + * nextHandlerPtr field is updated if the handler being pointed to is deleted. + * The nextPtr field is used to chain together all recursive invocations, so + * that Tcl_DeleteChannelHandler can find all the recursively nested + * invocations of ChannelHandlerEventProc and compare the handler being + * deleted against the NEXT handler to be invoked in that invocation; when it + * finds such a situation, Tcl_DeleteChannelHandler updates the nextHandlerPtr + * field of the structure to the next handler. + */ + +typedef struct NextChannelHandler { + ChannelHandler *nextHandlerPtr; /* The next handler to be invoked in + * this invocation. */ + struct NextChannelHandler *nestedHandlerPtr; + /* Next nested invocation of + * ChannelHandlerEventProc. */ +} NextChannelHandler; + +/* + * The following structure describes the event that is added to the Tcl + * event queue by the channel handler check procedure. + */ + +typedef struct ChannelHandlerEvent { + Tcl_Event header; /* Standard header for all events. */ + Channel *chanPtr; /* The channel that is ready. */ + int readyMask; /* Events that have occurred. */ +} ChannelHandlerEvent; + +/* + * The following structure is used by Tcl_GetsObj() to encapsulates the + * state for a "gets" operation. + */ + +typedef struct GetsState { + Tcl_Obj *objPtr; /* The object to which UTF-8 characters + * will be appended. */ + char **dstPtr; /* Pointer into objPtr's string rep where + * next character should be stored. */ + Tcl_Encoding encoding; /* The encoding to use to convert raw bytes + * to UTF-8. */ + ChannelBuffer *bufPtr; /* The current buffer of raw bytes being + * emptied. */ + Tcl_EncodingState state; /* The encoding state just before the last + * external to UTF-8 conversion in + * FilterInputBytes(). */ + int rawRead; /* The number of bytes removed from bufPtr + * in the last call to FilterInputBytes(). */ + int bytesWrote; /* The number of bytes of UTF-8 data + * appended to objPtr during the last call to + * FilterInputBytes(). */ + int charsWrote; /* The corresponding number of UTF-8 + * characters appended to objPtr during the + * last call to FilterInputBytes(). */ + int totalChars; /* The total number of UTF-8 characters + * appended to objPtr so far, just before the + * last call to FilterInputBytes(). */ +} GetsState; + +/* + * The following structure encapsulates the state for a background channel + * copy. Note that the data buffer for the copy will be appended to this + * structure. + */ + +typedef struct CopyState { + struct Channel *readPtr; /* Pointer to input channel. */ + struct Channel *writePtr; /* Pointer to output channel. */ + int readFlags; /* Original read channel flags. */ + int writeFlags; /* Original write channel flags. */ + int toRead; /* Number of bytes to copy, or -1. */ + Tcl_WideInt total; /* Total bytes transferred (written). */ + Tcl_Interp *interp; /* Interp that started the copy. */ + Tcl_Obj *cmdPtr; /* Command to be invoked at completion. */ + int bufSize; /* Size of appended buffer. */ + char buffer[1]; /* Copy buffer, this must be the last + * field. */ +} CopyState; + +/* * All static variables used in this file are collected into a single instance * of the following structure. For multi-threaded implementations, there is * one instance of this structure for each thread. |