merge-file.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
   7 static int fill_mmfile_blob(mmfile_t *f, struct blob *obj)
   8 {
   9         void *buf;
  10         unsigned long size;
  11         enum object_type type;
  12
  13         buf = read_sha1_file(obj->object.sha1, &type, &size);
  14         if (!buf)
  15                 return -1;
  16         if (type != OBJ_BLOB)
  17                 return -1;
  18         f->ptr = buf;
  19         f->size = size;
  20         return 0;
  21 }
  22
  23 static void free_mmfile(mmfile_t *f)
  24 {
  25         free(f->ptr);
  26 }
  27
  28 static void *three_way_filemerge(const char *path, mmfile_t *base, mmfile_t *our, mmfile_t *their, unsigned long *size)
  29 {
  30         int merge_status;
  31         mmbuffer_t res;
  32
  33         merge_status = ll_merge(&res, path, base,
  34                                 our, ".our", their, ".their", 0);
  35         if (merge_status < 0)
  36                 return NULL;
  37
  38         *size = res.size;
  39         return res.ptr;
  40 }
  41
  42 static int common_outf(void *priv_, mmbuffer_t *mb, int nbuf)
  43 {
  44         int i;
  45         mmfile_t *dst = priv_;
  46
  47         for (i = 0; i < nbuf; i++) {
  48                 memcpy(dst->ptr + dst->size, mb[i].ptr, mb[i].size);
  49                 dst->size += mb[i].size;
  50         }
  51         return 0;
  52 }
  53
  54 static int generate_common_file(mmfile_t *res, mmfile_t *f1, mmfile_t *f2)
  55 {
  56         unsigned long size = f1->size < f2->size ? f1->size : f2->size;
  57         void *ptr = xmalloc(size);
  58         xpparam_t xpp;
  59         xdemitconf_t xecfg;
  60         xdemitcb_t ecb;
  61
  62         memset(&xpp, 0, sizeof(xpp));
  63         xpp.flags = XDF_NEED_MINIMAL;
  64         memset(&xecfg, 0, sizeof(xecfg));
  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 xdi_diff(f1, f2, &xpp, &xecfg, &ecb);
  74 }
  75
  76 void *merge_file(const char *path, 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(path, &common, &f1, &f2, size);
 110         free_mmfile(&common);
 111 out_free_f2_f1:
 112         free_mmfile(&f2);
 113 out_free_f1:
 114         free_mmfile(&f1);
 115 out_no_mmfile:
 116         return res;
 117 }