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00022 #include <stdio.h>
00023 #include <stdlib.h>
00024 #include <string.h>
00025
00026 #include "probe-buffer.h"
00027
00028 typedef struct
00029 {
00030 const gchar * filename, * decoder;
00031 VFSFile * file;
00032 guchar buffer[16384];
00033 gint filled, at;
00034 const gchar * read_warned, * seek_warned;
00035 }
00036 ProbeBuffer;
00037
00038 static gint probe_buffer_fclose (VFSFile * file)
00039 {
00040 gint ret = vfs_fclose (((ProbeBuffer *) file->handle)->file);
00041 g_free (file->handle);
00042 return ret;
00043 }
00044
00045 static void increase_buffer (ProbeBuffer * p, gint64 size)
00046 {
00047 size = (size + 0xFF) & ~0xFF;
00048
00049 if (size > sizeof p->buffer)
00050 {
00051 if (p->read_warned != p->decoder)
00052 {
00053 fprintf (stderr, "%s tried to read past end of buffer while "
00054 "probing %s.\n", p->decoder, p->filename);
00055 p->read_warned = p->decoder;
00056 }
00057
00058 size = sizeof p->buffer;
00059 }
00060
00061 if (p->filled < size)
00062 p->filled += vfs_fread (p->buffer + p->at, 1, size - p->filled, p->file);
00063 }
00064
00065 static gint64 probe_buffer_fread (void * buffer, gint64 size, gint64 count,
00066 VFSFile * file)
00067 {
00068 ProbeBuffer * p = file->handle;
00069
00070 increase_buffer (p, p->at + size * count);
00071 gint readed = (size > 0) ? MIN (count, (p->filled - p->at) / size) : 0;
00072 memcpy (buffer, p->buffer + p->at, size * readed);
00073
00074 p->at += size * readed;
00075 return readed;
00076 }
00077
00078 static gint64 probe_buffer_fwrite (const void * data, gint64 size, gint64 count,
00079 VFSFile * file)
00080 {
00081
00082 return 0;
00083 }
00084
00085 static gint probe_buffer_getc (VFSFile * file)
00086 {
00087 guchar c;
00088 return (probe_buffer_fread (& c, 1, 1, file) == 1) ? c : EOF;
00089 }
00090
00091 static gint probe_buffer_fseek (VFSFile * file, gint64 offset, gint whence)
00092 {
00093 ProbeBuffer * p = file->handle;
00094
00095 if (whence == SEEK_END)
00096 {
00097 if (p->seek_warned != p->decoder)
00098 {
00099 fprintf (stderr, "%s tried to seek to end of file while probing "
00100 "%s.\n", p->decoder, p->filename);
00101 p->seek_warned = p->decoder;
00102 }
00103
00104 return -1;
00105 }
00106
00107 if (whence == SEEK_CUR)
00108 offset += p->at;
00109
00110 g_return_val_if_fail (offset >= 0, -1);
00111 increase_buffer (p, offset);
00112
00113 if (offset > p->filled)
00114 return -1;
00115
00116 p->at = offset;
00117 return 0;
00118 }
00119
00120 static gint probe_buffer_ungetc (gint c, VFSFile * file)
00121 {
00122 return (! probe_buffer_fseek (file, -1, SEEK_CUR)) ? c : EOF;
00123 }
00124
00125 static void probe_buffer_rewind (VFSFile * file)
00126 {
00127 probe_buffer_fseek (file, 0, SEEK_SET);
00128 }
00129
00130 static gint64 probe_buffer_ftell (VFSFile * file)
00131 {
00132 return ((ProbeBuffer *) file->handle)->at;
00133 }
00134
00135 static gboolean probe_buffer_feof (VFSFile * file)
00136 {
00137 ProbeBuffer * p = file->handle;
00138 return (p->at < p->filled) ? FALSE : vfs_feof (p->file);
00139 }
00140
00141 static gint probe_buffer_ftruncate (VFSFile * file, gint64 size)
00142 {
00143
00144 return -1;
00145 }
00146
00147 static gint64 probe_buffer_fsize (VFSFile * file)
00148 {
00149 return vfs_fsize (((ProbeBuffer *) file->handle)->file);
00150 }
00151
00152 static gchar * probe_buffer_get_metadata (VFSFile * file, const gchar * field)
00153 {
00154 return vfs_get_metadata (((ProbeBuffer *) file->handle)->file, field);
00155 }
00156
00157 static VFSConstructor probe_buffer_table =
00158 {
00159 .uri_id = NULL,
00160 .vfs_fopen_impl = NULL,
00161 .vfs_fclose_impl = probe_buffer_fclose,
00162 .vfs_fread_impl = probe_buffer_fread,
00163 .vfs_fwrite_impl = probe_buffer_fwrite,
00164 .vfs_getc_impl = probe_buffer_getc,
00165 .vfs_ungetc_impl = probe_buffer_ungetc,
00166 .vfs_fseek_impl = probe_buffer_fseek,
00167 .vfs_rewind_impl = probe_buffer_rewind,
00168 .vfs_ftell_impl = probe_buffer_ftell,
00169 .vfs_feof_impl = probe_buffer_feof,
00170 .vfs_ftruncate_impl = probe_buffer_ftruncate,
00171 .vfs_fsize_impl = probe_buffer_fsize,
00172 .vfs_get_metadata_impl = probe_buffer_get_metadata,
00173 };
00174
00175 VFSFile * probe_buffer_new (const gchar * filename)
00176 {
00177 VFSFile * file = vfs_fopen (filename, "r");
00178
00179 if (! file)
00180 return NULL;
00181
00182 ProbeBuffer * p = g_malloc (sizeof (ProbeBuffer));
00183 p->decoder = NULL;
00184 p->filename = filename;
00185 p->file = file;
00186 p->filled = 0;
00187 p->at = 0;
00188 p->read_warned = NULL;
00189 p->seek_warned = NULL;
00190
00191 VFSFile * file2 = g_malloc (sizeof (VFSFile));
00192 file2->base = & probe_buffer_table;
00193 file2->handle = p;
00194 file2->uri = g_strdup (filename);
00195 file2->ref = 1;
00196
00197 return file2;
00198 }
00199
00200 void probe_buffer_set_decoder (VFSFile * file, const gchar * decoder)
00201 {
00202 ProbeBuffer * p = file->handle;
00203 p->decoder = decoder;
00204 }