git/merge-file.c

118 lines
2.3 KiB
C
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#include "cache.h"
#include "run-command.h"
#include "xdiff-interface.h"
#include "blob.h"
static int fill_mmfile_blob(mmfile_t *f, struct blob *obj)
{
void *buf;
unsigned long size;
enum object_type type;
buf = read_sha1_file(obj->object.sha1, &type, &size);
if (!buf)
return -1;
if (type != OBJ_BLOB)
return -1;
f->ptr = buf;
f->size = size;
return 0;
}
static void free_mmfile(mmfile_t *f)
{
free(f->ptr);
}
static void *three_way_filemerge(mmfile_t *base, mmfile_t *our, mmfile_t *their, unsigned long *size)
{
mmbuffer_t res;
xpparam_t xpp;
int merge_status;
memset(&xpp, 0, sizeof(xpp));
merge_status = xdl_merge(base, our, ".our", their, ".their",
&xpp, XDL_MERGE_ZEALOUS, &res);
if (merge_status < 0)
return NULL;
*size = res.size;
return res.ptr;
}
static int common_outf(void *priv_, mmbuffer_t *mb, int nbuf)
{
int i;
mmfile_t *dst = priv_;
for (i = 0; i < nbuf; i++) {
memcpy(dst->ptr + dst->size, mb[i].ptr, mb[i].size);
dst->size += mb[i].size;
}
return 0;
}
static int generate_common_file(mmfile_t *res, mmfile_t *f1, mmfile_t *f2)
{
unsigned long size = f1->size < f2->size ? f1->size : f2->size;
void *ptr = xmalloc(size);
xpparam_t xpp;
xdemitconf_t xecfg;
xdemitcb_t ecb;
xpp.flags = XDF_NEED_MINIMAL;
xecfg.ctxlen = 3;
xecfg.flags = XDL_EMIT_COMMON;
ecb.outf = common_outf;
res->ptr = ptr;
res->size = 0;
ecb.priv = res;
return xdl_diff(f1, f2, &xpp, &xecfg, &ecb);
}
void *merge_file(struct blob *base, struct blob *our, struct blob *their, unsigned long *size)
{
void *res = NULL;
mmfile_t f1, f2, common;
/*
* Removed in either branch?
*
* NOTE! This depends on the caller having done the
* proper warning about removing a file that got
* modified in the other branch!
*/
if (!our || !their) {
enum object_type type;
if (base)
return NULL;
if (!our)
our = their;
return read_sha1_file(our->object.sha1, &type, size);
}
if (fill_mmfile_blob(&f1, our) < 0)
goto out_no_mmfile;
if (fill_mmfile_blob(&f2, their) < 0)
goto out_free_f1;
if (base) {
if (fill_mmfile_blob(&common, base) < 0)
goto out_free_f2_f1;
} else {
if (generate_common_file(&common, &f1, &f2) < 0)
goto out_free_f2_f1;
}
res = three_way_filemerge(&common, &f1, &f2, size);
free_mmfile(&common);
out_free_f2_f1:
free_mmfile(&f2);
out_free_f1:
free_mmfile(&f1);
out_no_mmfile:
return res;
}