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00022 #include <glib.h>
00023 #include <stdlib.h>
00024 #include <string.h>
00025
00026 #include "debug.h"
00027 #include "probe-buffer.h"
00028
00029 typedef struct
00030 {
00031 VFSFile * file;
00032 unsigned char buffer[16384];
00033 int filled, at;
00034 }
00035 ProbeBuffer;
00036
00037 static int probe_buffer_fclose (VFSFile * file)
00038 {
00039 ProbeBuffer * p = vfs_get_handle (file);
00040
00041 int ret = vfs_fclose (p->file);
00042 g_slice_free (ProbeBuffer, p);
00043 return ret;
00044 }
00045
00046 static void increase_buffer (ProbeBuffer * p, int64_t size)
00047 {
00048 size = (size + 0xFF) & ~0xFF;
00049
00050 if (size > sizeof p->buffer)
00051 size = sizeof p->buffer;
00052
00053 if (p->filled < size)
00054 p->filled += vfs_fread (p->buffer + p->filled, 1, size - p->filled,
00055 p->file);
00056 }
00057
00058 static int64_t probe_buffer_fread (void * buffer, int64_t size, int64_t count,
00059 VFSFile * file)
00060 {
00061 ProbeBuffer * p = vfs_get_handle (file);
00062
00063 increase_buffer (p, p->at + size * count);
00064 int readed = (size > 0) ? MIN (count, (p->filled - p->at) / size) : 0;
00065 memcpy (buffer, p->buffer + p->at, size * readed);
00066
00067 p->at += size * readed;
00068 return readed;
00069 }
00070
00071 static int64_t probe_buffer_fwrite (const void * data, int64_t size, int64_t count,
00072 VFSFile * file)
00073 {
00074
00075 return 0;
00076 }
00077
00078 static int probe_buffer_getc (VFSFile * file)
00079 {
00080 unsigned char c;
00081 return (probe_buffer_fread (& c, 1, 1, file) == 1) ? c : EOF;
00082 }
00083
00084 static int probe_buffer_fseek (VFSFile * file, int64_t offset, int whence)
00085 {
00086 ProbeBuffer * p = vfs_get_handle (file);
00087
00088 if (whence == SEEK_END)
00089 return -1;
00090
00091 if (whence == SEEK_CUR)
00092 offset += p->at;
00093
00094 g_return_val_if_fail (offset >= 0, -1);
00095 increase_buffer (p, offset);
00096
00097 if (offset > p->filled)
00098 return -1;
00099
00100 p->at = offset;
00101 return 0;
00102 }
00103
00104 static int probe_buffer_ungetc (int c, VFSFile * file)
00105 {
00106 return (! probe_buffer_fseek (file, -1, SEEK_CUR)) ? c : EOF;
00107 }
00108
00109 static void probe_buffer_rewind (VFSFile * file)
00110 {
00111 probe_buffer_fseek (file, 0, SEEK_SET);
00112 }
00113
00114 static int64_t probe_buffer_ftell (VFSFile * file)
00115 {
00116 return ((ProbeBuffer *) vfs_get_handle (file))->at;
00117 }
00118
00119 static bool_t probe_buffer_feof (VFSFile * file)
00120 {
00121 ProbeBuffer * p = vfs_get_handle (file);
00122 return (p->at < p->filled) ? FALSE : vfs_feof (p->file);
00123 }
00124
00125 static int probe_buffer_ftruncate (VFSFile * file, int64_t size)
00126 {
00127
00128 return -1;
00129 }
00130
00131 static int64_t probe_buffer_fsize (VFSFile * file)
00132 {
00133 return vfs_fsize (((ProbeBuffer *) vfs_get_handle (file))->file);
00134 }
00135
00136 static char * probe_buffer_get_metadata (VFSFile * file, const char * field)
00137 {
00138 return vfs_get_metadata (((ProbeBuffer *) vfs_get_handle (file))->file, field);
00139 }
00140
00141 static VFSConstructor probe_buffer_table =
00142 {
00143 .vfs_fopen_impl = NULL,
00144 .vfs_fclose_impl = probe_buffer_fclose,
00145 .vfs_fread_impl = probe_buffer_fread,
00146 .vfs_fwrite_impl = probe_buffer_fwrite,
00147 .vfs_getc_impl = probe_buffer_getc,
00148 .vfs_ungetc_impl = probe_buffer_ungetc,
00149 .vfs_fseek_impl = probe_buffer_fseek,
00150 .vfs_rewind_impl = probe_buffer_rewind,
00151 .vfs_ftell_impl = probe_buffer_ftell,
00152 .vfs_feof_impl = probe_buffer_feof,
00153 .vfs_ftruncate_impl = probe_buffer_ftruncate,
00154 .vfs_fsize_impl = probe_buffer_fsize,
00155 .vfs_get_metadata_impl = probe_buffer_get_metadata,
00156 };
00157
00158 VFSFile * probe_buffer_new (const char * filename)
00159 {
00160 VFSFile * file = vfs_fopen (filename, "r");
00161
00162 if (! file)
00163 return NULL;
00164
00165 ProbeBuffer * p = g_slice_new (ProbeBuffer);
00166 p->file = file;
00167 p->filled = 0;
00168 p->at = 0;
00169
00170 return vfs_new (filename, & probe_buffer_table, p);
00171 }