Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "run-command.h"
   3#include "xdiff-interface.h"
   4#include "blob.h"
   5
   6static int fill_mmfile_blob(mmfile_t *f, struct blob *obj)
   7{
   8        void *buf;
   9        unsigned long size;
  10        enum object_type type;
  11
  12        buf = read_sha1_file(obj->object.sha1, &type, &size);
  13        if (!buf)
  14                return -1;
  15        if (type != OBJ_BLOB)
  16                return -1;
  17        f->ptr = buf;
  18        f->size = size;
  19        return 0;
  20}
  21
  22static void free_mmfile(mmfile_t *f)
  23{
  24        free(f->ptr);
  25}
  26
  27static void *three_way_filemerge(mmfile_t *base, mmfile_t *our, mmfile_t *their, unsigned long *size)
  28{
  29        mmbuffer_t res;
  30        xpparam_t xpp;
  31        int merge_status;
  32
  33        memset(&xpp, 0, sizeof(xpp));
  34        merge_status = xdl_merge(base, our, ".our", their, ".their",
  35                &xpp, XDL_MERGE_ZEALOUS, &res);
  36
  37        if (merge_status < 0)
  38                return NULL;
  39
  40        *size = res.size;
  41        return res.ptr;
  42}
  43
  44static int common_outf(void *priv_, mmbuffer_t *mb, int nbuf)
  45{
  46        int i;
  47        mmfile_t *dst = priv_;
  48
  49        for (i = 0; i < nbuf; i++) {
  50                memcpy(dst->ptr + dst->size, mb[i].ptr, mb[i].size);
  51                dst->size += mb[i].size;
  52        }
  53        return 0;
  54}
  55
  56static int generate_common_file(mmfile_t *res, mmfile_t *f1, mmfile_t *f2)
  57{
  58        unsigned long size = f1->size < f2->size ? f1->size : f2->size;
  59        void *ptr = xmalloc(size);
  60        xpparam_t xpp;
  61        xdemitconf_t xecfg;
  62        xdemitcb_t ecb;
  63
  64        xpp.flags = XDF_NEED_MINIMAL;
  65        xecfg.ctxlen = 3;
  66        xecfg.flags = XDL_EMIT_COMMON;
  67        ecb.outf = common_outf;
  68
  69        res->ptr = ptr;
  70        res->size = 0;
  71
  72        ecb.priv = res;
  73        return xdl_diff(f1, f2, &xpp, &xecfg, &ecb);
  74}
  75
  76void *merge_file(struct blob *base, struct blob *our, struct blob *their, unsigned long *size)
  77{
  78        void *res = NULL;
  79        mmfile_t f1, f2, common;
  80
  81        /*
  82         * Removed in either branch?
  83         *
  84         * NOTE! This depends on the caller having done the
  85         * proper warning about removing a file that got
  86         * modified in the other branch!
  87         */
  88        if (!our || !their) {
  89                enum object_type type;
  90                if (base)
  91                        return NULL;
  92                if (!our)
  93                        our = their;
  94                return read_sha1_file(our->object.sha1, &type, size);
  95        }
  96
  97        if (fill_mmfile_blob(&f1, our) < 0)
  98                goto out_no_mmfile;
  99        if (fill_mmfile_blob(&f2, their) < 0)
 100                goto out_free_f1;
 101
 102        if (base) {
 103                if (fill_mmfile_blob(&common, base) < 0)
 104                        goto out_free_f2_f1;
 105        } else {
 106                if (generate_common_file(&common, &f1, &f2) < 0)
 107                        goto out_free_f2_f1;
 108        }
 109        res = three_way_filemerge(&common, &f1, &f2, size);
 110        free_mmfile(&common);
 111out_free_f2_f1:
 112        free_mmfile(&f2);
 113out_free_f1:
 114        free_mmfile(&f1);
 115out_no_mmfile:
 116        return res;
 117}