merge-blobs.c

   1 #include "cache.h"
   2 #include "run-command.h"
   3 #include "xdiff-interface.h"
   4 #include "ll-merge.h"
   5 #include "blob.h"
   6 #include "merge-blobs.h"
   7 #include "object-store.h"
   8
   9 static int fill_mmfile_blob(mmfile_t *f, struct blob *obj)
  10 {
  11         void *buf;
  12         unsigned long size;
  13         enum object_type type;
  14
  15         buf = read_object_file(&obj->object.oid, &type, &size);
  16         if (!buf)
  17                 return -1;
  18         if (type != OBJ_BLOB) {
  19                 free(buf);
  20                 return -1;
  21         }
  22         f->ptr = buf;
  23         f->size = size;
  24         return 0;
  25 }
  26
  27 static void free_mmfile(mmfile_t *f)
  28 {
  29         free(f->ptr);
  30 }
  31
  32 static void *three_way_filemerge(const char *path, mmfile_t *base, mmfile_t *our, mmfile_t *their, unsigned long *size)
  33 {
  34         int merge_status;
  35         mmbuffer_t res;
  36
  37         /*
  38          * This function is only used by cmd_merge_tree, which
  39          * does not respect the merge.conflictstyle option.
  40          * There is no need to worry about a label for the
  41          * common ancestor.
  42          */
  43         merge_status = ll_merge(&res, path, base, NULL,
  44                                 our, ".our", their, ".their", NULL);
  45         if (merge_status < 0)
  46                 return NULL;
  47
  48         *size = res.size;
  49         return res.ptr;
  50 }
  51
  52 void *merge_blobs(const char *path, struct blob *base, struct blob *our, struct blob *their, unsigned long *size)
  53 {
  54         void *res = NULL;
  55         mmfile_t f1, f2, common;
  56
  57         /*
  58          * Removed in either branch?
  59          *
  60          * NOTE! This depends on the caller having done the
  61          * proper warning about removing a file that got
  62          * modified in the other branch!
  63          */
  64         if (!our || !their) {
  65                 enum object_type type;
  66                 if (base)
  67                         return NULL;
  68                 if (!our)
  69                         our = their;
  70                 return read_object_file(&our->object.oid, &type, size);
  71         }
  72
  73         if (fill_mmfile_blob(&f1, our) < 0)
  74                 goto out_no_mmfile;
  75         if (fill_mmfile_blob(&f2, their) < 0)
  76                 goto out_free_f1;
  77
  78         if (base) {
  79                 if (fill_mmfile_blob(&common, base) < 0)
  80                         goto out_free_f2_f1;
  81         } else {
  82                 common.ptr = xstrdup("");
  83                 common.size = 0;
  84         }
  85         res = three_way_filemerge(path, &common, &f1, &f2, size);
  86         free_mmfile(&common);
  87 out_free_f2_f1:
  88         free_mmfile(&f2);
  89 out_free_f1:
  90         free_mmfile(&f1);
  91 out_no_mmfile:
  92         return res;
  93 }