convert object type handling from a string to a number
[git/git.git] / merge-file.c
1 #include "cache.h"
2 #include "run-command.h"
3 #include "xdiff-interface.h"
4 #include "blob.h"
5
6 static 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
22 static void free_mmfile(mmfile_t *f)
23 {
24 free(f->ptr);
25 }
26
27 static 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
44 static 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
56 static 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
76 void *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);
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 }