[Cvs-cvs] Changes to ccvs/src/buffer.h [signed-commits2]

[Derek Robert Price]

Index: ccvs/src/buffer.h
diff -u /dev/null ccvs/src/buffer.h:1.26.4.1
--- /dev/null   Thu Oct 20 21:33:55 2005
+++ ccvs/src/buffer.h   Thu Oct 20 21:33:10 2005
@@ -0,0 +1,208 @@
+/*
+ * Copyright (C) 1996-2005 The Free Software Foundation, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/* Declarations concerning the buffer data structure.  */
+
+#ifndef BUFFER_H
+#define BUFFER_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <sys/types.h>
+
+#include "root.h"
+
+#if defined (SERVER_SUPPORT) || defined (CLIENT_SUPPORT)
+
+# include "getpagesize.h"
+
+/*
+ * We must read data from a child process and send it across the
+ * network.  We do not want to block on writing to the network, so we
+ * store the data from the child process in memory.  A BUFFER
+ * structure holds the status of one communication, and uses a linked
+ * list of buffer_data structures to hold data.
+ */
+
+struct buffer;
+
+typedef int (*type_buf_input) (void *, char *, size_t, size_t, size_t *);
+typedef int (*type_buf_output) (void *, const char *, size_t, size_t *);
+typedef int (*type_buf_flush) (void *);
+typedef int (*type_buf_block) (void *, bool);
+typedef int (*type_buf_get_fd) (void *);
+typedef int (*type_buf_shutdown) (struct buffer *);
+typedef void (*type_buf_memory_error) (struct buffer *);
+
+struct buffer
+{
+    /* Data.  */
+    struct buffer_data *data;
+
+    /* Last buffer on data chain.  */
+    struct buffer_data *last;
+
+    /* Nonzero if the buffer is in nonblocking mode.  */
+    bool nonblocking;
+
+    /* Functions must be provided to transfer data in and out of the
+       buffer.  Either the input or output field must be set, but not
+       both.  */
+
+    /* Read data into the buffer DATA.  There is room for up to SIZE
+       bytes.  In blocking mode, wait until some input, at least NEED
+       bytes, is available (NEED may be 0 but that is the same as NEED
+       == 1).  In non-blocking mode return immediately no matter how
+       much input is available; NEED is ignored. Return 0 on success,
+       or -1 on end of file, or an errno code.  Set the number of
+       bytes read in *GOT.
+       
+       If there are a nonzero number of bytes available, less than NEED,
+       followed by end of file, just read those bytes and return 0.  */
+    type_buf_input input;
+
+    /* Write data.  This should write up to HAVE bytes from DATA.
+       This should return 0 on success, or an errno code.  It should
+       set the number of bytes written in *WROTE.  */
+    type_buf_output output;
+
+    /* Flush any data which may be buffered up after previous calls to
+       OUTPUT.  This should return 0 on success, or an errno code.  */
+    type_buf_flush flush;
+
+    /* Change the blocking mode of the underlying communication
+       stream.  If BLOCK is non-zero, it should be placed into
+       blocking mode.  Otherwise, it should be placed into
+       non-blocking mode.  This should return 0 on success, or an
+       errno code.  */
+    type_buf_block block;
+
+    /* Return the file descriptor underlying this buffer, if any, or -1
+     * otherwise.
+     */
+    type_buf_get_fd get_fd;
+
+    /* Shut down the communication stream.  This does not mean that it
+       should be closed.  It merely means that no more data will be
+       read or written, and that any final processing that is
+       appropriate should be done at this point.  This may be NULL.
+       It should return 0 on success, or an errno code.  This entry
+       point exists for the compression code.  */
+    type_buf_shutdown shutdown;
+
+    /* This field is passed to the INPUT, OUTPUT, and BLOCK functions.  */
+    void *closure;
+
+    /* Function to call if we can't allocate memory.  */
+    type_buf_memory_error memory_error;
+};
+
+/* Data is stored in lists of these structures.  */
+
+struct buffer_data
+{
+    /* Next buffer in linked list.  */
+    struct buffer_data *next;
+
+    /*
+     * A pointer into the data area pointed to by the text field.  This
+     * is where to find data that has not yet been written out.
+     */
+    char *bufp;
+
+    /* The number of data bytes found at BUFP.  */
+    size_t size;
+
+    /*
+     * Actual buffer.  This never changes after the structure is
+     * allocated.  The buffer is BUFFER_DATA_SIZE bytes.
+     */
+    char *text;
+};
+
+/* The size we allocate for each buffer_data structure.  */
+#define BUFFER_DATA_SIZE getpagesize ()
+
+/* The type of a function passed as a memory error handler.  */
+typedef void (*BUFMEMERRPROC) (struct buffer *);
+
+struct buffer *buf_initialize (type_buf_input,
+                               type_buf_output,
+                               type_buf_flush,
+                               type_buf_block,
+                               type_buf_get_fd,
+                               type_buf_shutdown,
+                               type_buf_memory_error,
+                               void *);
+void buf_free (struct buffer *);
+struct buffer *buf_nonio_initialize (void (*) (struct buffer *));
+struct buffer *compress_buffer_initialize (struct buffer *, int, int,
+                                          void (*) (struct buffer *));
+struct buffer *packetizing_buffer_initialize
+       (struct buffer *, int (*) (void *, const char *, char *, size_t),
+        int (*) (void *, const char *, char *, size_t, size_t *), void *,
+        void (*) (struct buffer *));
+int buf_empty (struct buffer *);
+int buf_empty_p (struct buffer *);
+void buf_output (struct buffer *, const char *, size_t);
+void buf_output0 (struct buffer *, const char *);
+void buf_append_char (struct buffer *, int);
+int buf_send_output (struct buffer *);
+int buf_flush (struct buffer *, bool);
+int set_nonblock (struct buffer *);
+int set_block (struct buffer *);
+int buf_send_counted (struct buffer *);
+int buf_send_special_count (struct buffer *, int);
+void buf_append_data (struct buffer *, struct buffer_data *,
+                     struct buffer_data *);
+void buf_append_buffer (struct buffer *, struct buffer *);
+int buf_read_file (FILE *, long, struct buffer_data **, struct buffer_data **);
+int buf_read_file_to_eof (FILE *, struct buffer_data **,
+                         struct buffer_data **);
+int buf_input_data (struct buffer *, size_t *);
+int buf_read_line (struct buffer *, char **, size_t *);
+int buf_read_short_line (struct buffer *buf, char **line, size_t *lenp,
+                         size_t max);
+int buf_read_data (struct buffer *, size_t, char **, size_t *);
+void buf_copy_lines (struct buffer *, struct buffer *, int);
+int buf_copy_counted (struct buffer *, struct buffer *, int *);
+int buf_chain_length (struct buffer_data *);
+int buf_length (struct buffer *);
+int buf_get_fd (struct buffer *);
+int buf_shutdown (struct buffer *);
+#ifdef PROXY_SUPPORT
+void buf_copy_data (struct buffer *buf, struct buffer_data *data,
+                    struct buffer_data *last);
+#endif /* PROXY_SUPPORT */
+void buf_free_data (struct buffer *);
+
+#ifdef SERVER_FLOWCONTROL
+int buf_count_mem (struct buffer *);
+#endif /* SERVER_FLOWCONTROL */
+
+struct buffer *
+fd_buffer_initialize (int fd, pid_t child_pid, cvsroot_t *root, bool input,
+                      void (*memory) (struct buffer *));
+
+/* EWOULDBLOCK is not defined by POSIX, but some BSD systems will
+   return it, rather than EAGAIN, for nonblocking writes.  */
+# ifdef EWOULDBLOCK
+#   define blocking_error(err) ((err) == EWOULDBLOCK || (err) == EAGAIN)
+# else
+#   define blocking_error(err) ((err) == EAGAIN)
+# endif
+#endif /* defined (SERVER_SUPPORT) || defined (CLIENT_SUPPORT) */
+
+#endif /* BUFFER_H */