write_common.c

   1 /*
   2  * Copyright (C) 2006 Andre Noll <maan@systemlinux.org>
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     This program is distributed in the hope that it will be useful,
  10  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *     GNU General Public License for more details.
  13  *
  14  *     You should have received a copy of the GNU General Public License
  15  *     along with this program; if not, write to the Free Software
  16  *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  17  */
  18
  19 #include "para.h"
  20 #include "string.h"
  21 #include "write.h"
  22 #include "error.h"
  23
  24 const char *writer_names[] ={WRITER_NAMES};
  25 struct writer writers[NUM_SUPPORTED_WRITERS] = {WRITER_ARRAY};
  26
  27 int wng_write(struct writer_node_group *g, char *buf, size_t *loaded)
  28 {
  29         int ret, i, need_more_writes = 1;
  30         size_t min_written = 0;
  31
  32         while (need_more_writes) {
  33                 need_more_writes = 0;
  34                 FOR_EACH_WRITER_NODE(i, g) {
  35                         size_t w = g->written[i];
  36                         unsigned char *p = buf + w;
  37                         int bytes_to_write;
  38                         struct writer_node *wn = &g->writer_nodes[i];
  39                         if (!i)
  40                                 min_written = w;
  41                         else
  42                                 min_written = PARA_MIN(min_written, w);
  43                         if (w == *loaded)
  44                                 continue;
  45                         if (!g->eof && (*loaded < wn->chunk_bytes + w))
  46                                 continue;
  47                         bytes_to_write = PARA_MIN(wn->chunk_bytes,
  48                                 *loaded - w);
  49                         ret = wn->writer->write(p, bytes_to_write, wn);
  50                         if (ret < 0)
  51                                 goto out;
  52                         if (ret != bytes_to_write)
  53                                 PARA_WARNING_LOG("short write: %d/%d\n", ret,
  54                                         bytes_to_write);
  55                         g->written[i] += ret;
  56                         need_more_writes = 1;
  57                 }
  58         }
  59         *loaded -= min_written;
  60         ret = 0;
  61         if (g->eof)
  62                 goto out;
  63         if (*loaded)
  64                 memmove(buf, buf + min_written, *loaded);
  65         FOR_EACH_WRITER_NODE(i, g)
  66                 g->written[i] -= min_written;
  67         ret = 1;
  68 out:
  69         return ret;
  70 }
  71
  72 int wng_open(struct writer_node_group *g)
  73 {
  74         int i, ret = 1;
  75
  76         FOR_EACH_WRITER_NODE(i, g) {
  77                 struct writer_node *wn = &g->writer_nodes[i];
  78                 ret = wn->writer->open(wn);
  79                 if (ret < 0)
  80                         goto out;
  81                 wn->chunk_bytes = ret;
  82                 g->max_chunk_bytes = PARA_MAX(g->max_chunk_bytes, ret);
  83         }
  84 out:
  85         return ret;
  86 }
  87
  88 void wng_close(struct writer_node_group *g)
  89 {
  90         int i;
  91
  92         FOR_EACH_WRITER_NODE(i, g) {
  93                 struct writer_node *wn = &g->writer_nodes[i];
  94                 wn->writer->close(wn);
  95         }
  96 }
  97
  98 struct writer_node_group *wng_new(unsigned num_writers)
  99 {
 100         struct writer_node_group *g = para_calloc(sizeof(struct writer_node_group));
 101         g->num_writers = num_writers;
 102         g->writer_nodes = para_calloc(num_writers
 103                 * sizeof(struct writer_node));
 104         g->written = para_calloc(num_writers * sizeof(size_t));
 105         return g;
 106 }
 107
 108 void wng_destroy(struct writer_node_group *g)
 109 {
 110         if (!g)
 111                 return;
 112         free(g->written);
 113         free(g->writer_nodes);
 114         free(g);
 115 }
 116
 117 void init_supported_writers(void)
 118 {
 119         int i;
 120
 121         FOR_EACH_WRITER(i)
 122                 writers[i].init(&writers[i]);
 123 }
 124
 125 int check_writer_arg(const char *arg)
 126 {
 127         int i, ret = -E_WRITE_COMMON_SYNTAX;
 128         char *a = para_strdup(arg), *p = strchr(a, ':');
 129         if (p)
 130                 *p = '\0';
 131         p++;
 132         FOR_EACH_WRITER(i) {
 133                 if (strcmp(writer_names[i], a))
 134                         continue;
 135                 ret = i;
 136                 goto out;
 137         }
 138 out:
 139         free(a);
 140         return ret;
 141 }
 142
 143 struct writer_node_group *setup_default_wng(void)
 144 {
 145         struct writer_node_group *wng = wng_new(1);
 146         enum writer_enum default_writer;
 147
 148         if (NUM_SUPPORTED_WRITERS == 1)
 149                 default_writer = FILE_WRITE;
 150         else
 151                 default_writer = 1;
 152         wng->writer_nodes[0].writer = &writers[default_writer];
 153         PARA_INFO_LOG("using default writer: %s\n",
 154                 writer_names[default_writer]);
 155         return wng;
 156 }