external/gpl2/xcvs/dist/src/ms-buffer.c

   1 /* CVS client logging buffer.
   2
   3    This program is free software; you can redistribute it and/or modify
   4    it under the terms of the GNU General Public License as published by
   5    the Free Software Foundation; either version 2, or (at your option)
   6    any later version.
   7
   8    This program is distributed in the hope that it will be useful,
   9    but WITHOUT ANY WARRANTY; without even the implied warranty of
  10    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11    GNU General Public License for more details.  */
  12
  13 #include <config.h>
  14
  15 #include <stdio.h>
  16
  17 #include "cvs.h"
  18 #include "buffer.h"
  19 #include "ms-buffer.h"
  20
  21 #if defined (SERVER_SUPPORT) || defined (CLIENT_SUPPORT)
  22 #ifdef PROXY_SUPPORT
  23
  24 /* This structure is the closure field of a multi-source buffer.  */
  25 struct ms_buffer
  26 {
  27     /* Our buffer struct.  */
  28     struct buffer *buf;
  29
  30     /* The underlying buffers.  */
  31     struct buffer *cur;
  32     List *bufs;
  33
  34     /* Whether we are in blocking mode or not.  */
  35     bool block;
  36 };
  37
  38
  39
  40 /* The block function for a multi-source buffer.  */
  41 static int
  42 ms_buffer_block (void *closure, bool block)
  43 {
  44     struct ms_buffer *mb = closure;
  45
  46     mb->block = block;
  47     if (block)
  48         return set_block (mb->cur);
  49     else
  50         return set_nonblock (mb->cur);
  51 }
  52
  53
  54
  55 /* The input function for a log buffer.  */
  56 static int
  57 ms_buffer_input (void *closure, char *data, size_t need, size_t size,
  58                  size_t *got)
  59 {
  60     struct ms_buffer *mb = closure;
  61     int status;
  62
  63     assert (mb->cur->input);
  64     status = (*mb->cur->input) (mb->cur->closure, data, need, size, got);
  65     if (status == -1)
  66     {
  67         Node *p;
  68         /* EOF.  Set up the next buffer in line but return success and no
  69          * data since our caller may have selected on the target to find
  70          * ready data before calling us.
  71          *
  72          * If there are no more buffers, return EOF.
  73          */
  74         if (list_isempty (mb->bufs)) return -1;
  75         buf_shutdown (mb->cur);
  76         buf_free (mb->cur);
  77         p = mb->bufs->list->next;
  78         mb->cur = p->data;
  79         p->delproc = NULL;
  80         p->data = NULL;
  81         delnode (p);
  82         if (!buf_empty_p (mb->cur)) buf_append_buffer (mb->buf, mb->cur);
  83         ms_buffer_block (closure, mb->block);
  84         *got = 0;
  85         status = 0;
  86     }
  87
  88     return status;
  89 }
  90
  91
  92
  93 /* Return the file descriptor underlying any child buffers.  */
  94 static int
  95 ms_buffer_get_fd (void *closure)
  96 {
  97     struct ms_buffer *mb = closure;
  98     return buf_get_fd (mb->cur);
  99 }
 100
 101
 102
 103 /* The shutdown function for a multi-source buffer.  */
 104 static int
 105 ms_buffer_shutdown (struct buffer *buf)
 106 {
 107     struct ms_buffer *mb = buf->closure;
 108     Node *p;
 109     int err = 0;
 110
 111     assert (mb->cur);
 112     err += buf_shutdown (mb->cur);
 113     buf_free (mb->cur);
 114     for (p = mb->bufs->list->next; p != mb->bufs->list; p = p->next)
 115     {
 116         assert (p);
 117         err += buf_shutdown (p->data);
 118     }
 119
 120     dellist (&mb->bufs);
 121     return err;
 122 }
 123
 124
 125
 126 static void
 127 delbuflist (Node *p)
 128 {
 129     if (p->data)
 130         buf_free (p->data);
 131 }
 132
 133
 134
 135 /* Create a multi-source buffer.  This could easily be generalized to support
 136  * any number of source buffers, but for now only two are necessary.
 137  */
 138 struct buffer *
 139 ms_buffer_initialize (void (*memory) (struct buffer *),
 140                       struct buffer *buf, struct buffer *buf2/*, ...*/)
 141 {
 142     struct ms_buffer *mb = xmalloc (sizeof *mb);
 143     struct buffer *retbuf;
 144     Node *p;
 145
 146     mb->block = false;
 147     mb->cur = buf;
 148     set_nonblock (buf);
 149     mb->bufs = getlist ();
 150     p = getnode ();
 151     p->data = buf2;
 152     p->delproc = delbuflist;
 153     addnode (mb->bufs, p);
 154     retbuf = buf_initialize (ms_buffer_input, NULL, NULL,
 155                              ms_buffer_block, ms_buffer_get_fd,
 156                              ms_buffer_shutdown, memory, mb);
 157     if (!buf_empty_p (buf)) buf_append_buffer (retbuf, buf);
 158     mb->buf = retbuf;
 159
 160     return retbuf;
 161 }
 162 #endif /* PROXY_SUPPORT */
 163 #endif /* defined (SERVER_SUPPORT) || defined (CLIENT_SUPPORT) */