Add in-memory patch reading support

This commit is contained in:
TheSola10 2025-04-06 00:16:59 +02:00
parent 8f3dd9c61b
commit 21d43920da
Signed by: thesola10
GPG Key ID: 89245619BEBB95BA
2 changed files with 31 additions and 3 deletions

View File

@ -13,7 +13,7 @@
#include <stdlib.h>
#include "usage.rl.h"
#include "rdiff.h"
#include "compare.h"
int
umdiff_delta(char *source, char *target, char *output)
@ -33,6 +33,7 @@ umdiff_delta(char *source, char *target, char *output)
int
umdiff_patch(char *source, char *umdiff, char *output)
{
return 1;
}

View File

@ -12,7 +12,11 @@
#include "umdiff.h"
static long
#include <string.h>
static umdiff_File *current_file;
static int
_impl_umdiff_Command_read(umdiff_Command cmd, void *dest, long count, long offset,
umdiff_ReadCallback read_source,
umdiff_ReadCallback read_patchFile)
@ -48,17 +52,40 @@ _impl_umdiff_File_readIndexCmds(umdiff_File *file, long offset_sector,
file->last_index = index;
}
/**
* Virtual read callback for @ref umdiff_File with @ref umdiff_FileFlags_LOAD_FULL.
*
* Automatically set by @ref umdiff_File_readPatched as needed.
*/
int
_impl_umdiff_ReadCallback_fullFile(void *dest, long count, long offset)
{
// Undo relative-to-absolute translation from _impl_umdiff_Command_read
long ds = current_file->hdr.data_start;
long real_offset = offset - ds;
memcpy(dest, current_file->data + real_offset, count);
return count;
}
int
umdiff_File_readPatched(umdiff_File *file, void *dest, long count, long offset,
umdiff_ReadCallback read_source,
umdiff_ReadCallback read_patchFile)
{
long res;
int res;
umdiff_Command *commands;
umdiff_Command *curCommand;
#define $offset_sectors (offset / ISO_SECTOR_SIZE)
current_file = file;
if (file->mode == umdiff_FileFlags_LOAD_FULL) {
read_patchFile = _impl_umdiff_ReadCallback_fullFile;
}
while (count > 0) {
commands = _impl_umdiff_File_readIndexCmds(file, $offset_sectors,
read_patchFile);