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-rw-r--r--generic/tclIO.c102
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.