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-rw-r--r--range-diff.c435
1 files changed, 435 insertions, 0 deletions
diff --git a/range-diff.c b/range-diff.c
new file mode 100644
index 0000000000..b6b9abac26
--- /dev/null
+++ b/range-diff.c
@@ -0,0 +1,435 @@
+#include "cache.h"
+#include "range-diff.h"
+#include "string-list.h"
+#include "run-command.h"
+#include "argv-array.h"
+#include "hashmap.h"
+#include "xdiff-interface.h"
+#include "linear-assignment.h"
+#include "diffcore.h"
+#include "commit.h"
+#include "pretty.h"
+#include "userdiff.h"
+
+struct patch_util {
+ /* For the search for an exact match */
+ struct hashmap_entry e;
+ const char *diff, *patch;
+
+ int i, shown;
+ int diffsize;
+ size_t diff_offset;
+ /* the index of the matching item in the other branch, or -1 */
+ int matching;
+ struct object_id oid;
+};
+
+/*
+ * Reads the patches into a string list, with the `util` field being populated
+ * as struct object_id (will need to be free()d).
+ */
+static int read_patches(const char *range, struct string_list *list)
+{
+ struct child_process cp = CHILD_PROCESS_INIT;
+ FILE *in;
+ struct strbuf buf = STRBUF_INIT, line = STRBUF_INIT;
+ struct patch_util *util = NULL;
+ int in_header = 1;
+
+ argv_array_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
+ "--reverse", "--date-order", "--decorate=no",
+ "--no-abbrev-commit", range,
+ NULL);
+ cp.out = -1;
+ cp.no_stdin = 1;
+ cp.git_cmd = 1;
+
+ if (start_command(&cp))
+ return error_errno(_("could not start `log`"));
+ in = fdopen(cp.out, "r");
+ if (!in) {
+ error_errno(_("could not read `log` output"));
+ finish_command(&cp);
+ return -1;
+ }
+
+ while (strbuf_getline(&line, in) != EOF) {
+ const char *p;
+
+ if (skip_prefix(line.buf, "commit ", &p)) {
+ if (util) {
+ string_list_append(list, buf.buf)->util = util;
+ strbuf_reset(&buf);
+ }
+ util = xcalloc(sizeof(*util), 1);
+ if (get_oid(p, &util->oid)) {
+ error(_("could not parse commit '%s'"), p);
+ free(util);
+ string_list_clear(list, 1);
+ strbuf_release(&buf);
+ strbuf_release(&line);
+ fclose(in);
+ finish_command(&cp);
+ return -1;
+ }
+ util->matching = -1;
+ in_header = 1;
+ continue;
+ }
+
+ if (starts_with(line.buf, "diff --git")) {
+ in_header = 0;
+ strbuf_addch(&buf, '\n');
+ if (!util->diff_offset)
+ util->diff_offset = buf.len;
+ strbuf_addbuf(&buf, &line);
+ } else if (in_header) {
+ if (starts_with(line.buf, "Author: ")) {
+ strbuf_addbuf(&buf, &line);
+ strbuf_addstr(&buf, "\n\n");
+ } else if (starts_with(line.buf, " ")) {
+ strbuf_rtrim(&line);
+ strbuf_addbuf(&buf, &line);
+ strbuf_addch(&buf, '\n');
+ }
+ continue;
+ } else if (starts_with(line.buf, "@@ "))
+ strbuf_addstr(&buf, "@@");
+ else if (!line.buf[0] || starts_with(line.buf, "index "))
+ /*
+ * A completely blank (not ' \n', which is context)
+ * line is not valid in a diff. We skip it
+ * silently, because this neatly handles the blank
+ * separator line between commits in git-log
+ * output.
+ *
+ * We also want to ignore the diff's `index` lines
+ * because they contain exact blob hashes in which
+ * we are not interested.
+ */
+ continue;
+ else
+ strbuf_addbuf(&buf, &line);
+
+ strbuf_addch(&buf, '\n');
+ util->diffsize++;
+ }
+ fclose(in);
+ strbuf_release(&line);
+
+ if (util)
+ string_list_append(list, buf.buf)->util = util;
+ strbuf_release(&buf);
+
+ if (finish_command(&cp))
+ return -1;
+
+ return 0;
+}
+
+static int patch_util_cmp(const void *dummy, const struct patch_util *a,
+ const struct patch_util *b, const char *keydata)
+{
+ return strcmp(a->diff, keydata ? keydata : b->diff);
+}
+
+static void find_exact_matches(struct string_list *a, struct string_list *b)
+{
+ struct hashmap map;
+ int i;
+
+ hashmap_init(&map, (hashmap_cmp_fn)patch_util_cmp, NULL, 0);
+
+ /* First, add the patches of a to a hash map */
+ for (i = 0; i < a->nr; i++) {
+ struct patch_util *util = a->items[i].util;
+
+ util->i = i;
+ util->patch = a->items[i].string;
+ util->diff = util->patch + util->diff_offset;
+ hashmap_entry_init(util, strhash(util->diff));
+ hashmap_add(&map, util);
+ }
+
+ /* Now try to find exact matches in b */
+ for (i = 0; i < b->nr; i++) {
+ struct patch_util *util = b->items[i].util, *other;
+
+ util->i = i;
+ util->patch = b->items[i].string;
+ util->diff = util->patch + util->diff_offset;
+ hashmap_entry_init(util, strhash(util->diff));
+ other = hashmap_remove(&map, util, NULL);
+ if (other) {
+ if (other->matching >= 0)
+ BUG("already assigned!");
+
+ other->matching = i;
+ util->matching = other->i;
+ }
+ }
+
+ hashmap_free(&map, 0);
+}
+
+static void diffsize_consume(void *data, char *line, unsigned long len)
+{
+ (*(int *)data)++;
+}
+
+static int diffsize(const char *a, const char *b)
+{
+ xpparam_t pp = { 0 };
+ xdemitconf_t cfg = { 0 };
+ mmfile_t mf1, mf2;
+ int count = 0;
+
+ mf1.ptr = (char *)a;
+ mf1.size = strlen(a);
+ mf2.ptr = (char *)b;
+ mf2.size = strlen(b);
+
+ cfg.ctxlen = 3;
+ if (!xdi_diff_outf(&mf1, &mf2, diffsize_consume, &count, &pp, &cfg))
+ return count;
+
+ error(_("failed to generate diff"));
+ return COST_MAX;
+}
+
+static void get_correspondences(struct string_list *a, struct string_list *b,
+ int creation_factor)
+{
+ int n = a->nr + b->nr;
+ int *cost, c, *a2b, *b2a;
+ int i, j;
+
+ ALLOC_ARRAY(cost, st_mult(n, n));
+ ALLOC_ARRAY(a2b, n);
+ ALLOC_ARRAY(b2a, n);
+
+ for (i = 0; i < a->nr; i++) {
+ struct patch_util *a_util = a->items[i].util;
+
+ for (j = 0; j < b->nr; j++) {
+ struct patch_util *b_util = b->items[j].util;
+
+ if (a_util->matching == j)
+ c = 0;
+ else if (a_util->matching < 0 && b_util->matching < 0)
+ c = diffsize(a_util->diff, b_util->diff);
+ else
+ c = COST_MAX;
+ cost[i + n * j] = c;
+ }
+
+ c = a_util->matching < 0 ?
+ a_util->diffsize * creation_factor / 100 : COST_MAX;
+ for (j = b->nr; j < n; j++)
+ cost[i + n * j] = c;
+ }
+
+ for (j = 0; j < b->nr; j++) {
+ struct patch_util *util = b->items[j].util;
+
+ c = util->matching < 0 ?
+ util->diffsize * creation_factor / 100 : COST_MAX;
+ for (i = a->nr; i < n; i++)
+ cost[i + n * j] = c;
+ }
+
+ for (i = a->nr; i < n; i++)
+ for (j = b->nr; j < n; j++)
+ cost[i + n * j] = 0;
+
+ compute_assignment(n, n, cost, a2b, b2a);
+
+ for (i = 0; i < a->nr; i++)
+ if (a2b[i] >= 0 && a2b[i] < b->nr) {
+ struct patch_util *a_util = a->items[i].util;
+ struct patch_util *b_util = b->items[a2b[i]].util;
+
+ a_util->matching = a2b[i];
+ b_util->matching = i;
+ }
+
+ free(cost);
+ free(a2b);
+ free(b2a);
+}
+
+static void output_pair_header(struct diff_options *diffopt,
+ int patch_no_width,
+ struct strbuf *buf,
+ struct strbuf *dashes,
+ struct patch_util *a_util,
+ struct patch_util *b_util)
+{
+ struct object_id *oid = a_util ? &a_util->oid : &b_util->oid;
+ struct commit *commit;
+ char status;
+ const char *color_reset = diff_get_color_opt(diffopt, DIFF_RESET);
+ const char *color_old = diff_get_color_opt(diffopt, DIFF_FILE_OLD);
+ const char *color_new = diff_get_color_opt(diffopt, DIFF_FILE_NEW);
+ const char *color_commit = diff_get_color_opt(diffopt, DIFF_COMMIT);
+ const char *color;
+
+ if (!dashes->len)
+ strbuf_addchars(dashes, '-',
+ strlen(find_unique_abbrev(oid,
+ DEFAULT_ABBREV)));
+
+ if (!b_util) {
+ color = color_old;
+ status = '<';
+ } else if (!a_util) {
+ color = color_new;
+ status = '>';
+ } else if (strcmp(a_util->patch, b_util->patch)) {
+ color = color_commit;
+ status = '!';
+ } else {
+ color = color_commit;
+ status = '=';
+ }
+
+ strbuf_reset(buf);
+ strbuf_addstr(buf, status == '!' ? color_old : color);
+ if (!a_util)
+ strbuf_addf(buf, "%*s: %s ", patch_no_width, "-", dashes->buf);
+ else
+ strbuf_addf(buf, "%*d: %s ", patch_no_width, a_util->i + 1,
+ find_unique_abbrev(&a_util->oid, DEFAULT_ABBREV));
+
+ if (status == '!')
+ strbuf_addf(buf, "%s%s", color_reset, color);
+ strbuf_addch(buf, status);
+ if (status == '!')
+ strbuf_addf(buf, "%s%s", color_reset, color_new);
+
+ if (!b_util)
+ strbuf_addf(buf, " %*s: %s", patch_no_width, "-", dashes->buf);
+ else
+ strbuf_addf(buf, " %*d: %s", patch_no_width, b_util->i + 1,
+ find_unique_abbrev(&b_util->oid, DEFAULT_ABBREV));
+
+ commit = lookup_commit_reference(the_repository, oid);
+ if (commit) {
+ if (status == '!')
+ strbuf_addf(buf, "%s%s", color_reset, color);
+
+ strbuf_addch(buf, ' ');
+ pp_commit_easy(CMIT_FMT_ONELINE, commit, buf);
+ }
+ strbuf_addf(buf, "%s\n", color_reset);
+
+ fwrite(buf->buf, buf->len, 1, stdout);
+}
+
+static struct userdiff_driver no_func_name = {
+ .funcname = { "$^", 0 }
+};
+
+static struct diff_filespec *get_filespec(const char *name, const char *p)
+{
+ struct diff_filespec *spec = alloc_filespec(name);
+
+ fill_filespec(spec, &null_oid, 0, 0644);
+ spec->data = (char *)p;
+ spec->size = strlen(p);
+ spec->should_munmap = 0;
+ spec->is_stdin = 1;
+ spec->driver = &no_func_name;
+
+ return spec;
+}
+
+static void patch_diff(const char *a, const char *b,
+ struct diff_options *diffopt)
+{
+ diff_queue(&diff_queued_diff,
+ get_filespec("a", a), get_filespec("b", b));
+
+ diffcore_std(diffopt);
+ diff_flush(diffopt);
+}
+
+static void output(struct string_list *a, struct string_list *b,
+ struct diff_options *diffopt)
+{
+ struct strbuf buf = STRBUF_INIT, dashes = STRBUF_INIT;
+ int patch_no_width = decimal_width(1 + (a->nr > b->nr ? a->nr : b->nr));
+ int i = 0, j = 0;
+
+ /*
+ * We assume the user is really more interested in the second argument
+ * ("newer" version). To that end, we print the output in the order of
+ * the RHS (the `b` parameter). To put the LHS (the `a` parameter)
+ * commits that are no longer in the RHS into a good place, we place
+ * them once we have shown all of their predecessors in the LHS.
+ */
+
+ while (i < a->nr || j < b->nr) {
+ struct patch_util *a_util, *b_util;
+ a_util = i < a->nr ? a->items[i].util : NULL;
+ b_util = j < b->nr ? b->items[j].util : NULL;
+
+ /* Skip all the already-shown commits from the LHS. */
+ while (i < a->nr && a_util->shown)
+ a_util = ++i < a->nr ? a->items[i].util : NULL;
+
+ /* Show unmatched LHS commit whose predecessors were shown. */
+ if (i < a->nr && a_util->matching < 0) {
+ output_pair_header(diffopt, patch_no_width,
+ &buf, &dashes, a_util, NULL);
+ i++;
+ continue;
+ }
+
+ /* Show unmatched RHS commits. */
+ while (j < b->nr && b_util->matching < 0) {
+ output_pair_header(diffopt, patch_no_width,
+ &buf, &dashes, NULL, b_util);
+ b_util = ++j < b->nr ? b->items[j].util : NULL;
+ }
+
+ /* Show matching LHS/RHS pair. */
+ if (j < b->nr) {
+ a_util = a->items[b_util->matching].util;
+ output_pair_header(diffopt, patch_no_width,
+ &buf, &dashes, a_util, b_util);
+ if (!(diffopt->output_format & DIFF_FORMAT_NO_OUTPUT))
+ patch_diff(a->items[b_util->matching].string,
+ b->items[j].string, diffopt);
+ a_util->shown = 1;
+ j++;
+ }
+ }
+ strbuf_release(&buf);
+ strbuf_release(&dashes);
+}
+
+int show_range_diff(const char *range1, const char *range2,
+ int creation_factor, struct diff_options *diffopt)
+{
+ int res = 0;
+
+ struct string_list branch1 = STRING_LIST_INIT_DUP;
+ struct string_list branch2 = STRING_LIST_INIT_DUP;
+
+ if (read_patches(range1, &branch1))
+ res = error(_("could not parse log for '%s'"), range1);
+ if (!res && read_patches(range2, &branch2))
+ res = error(_("could not parse log for '%s'"), range2);
+
+ if (!res) {
+ find_exact_matches(&branch1, &branch2);
+ get_correspondences(&branch1, &branch2, creation_factor);
+ output(&branch1, &branch2, diffopt);
+ }
+
+ string_list_clear(&branch1, 1);
+ string_list_clear(&branch2, 1);
+
+ return res;
+}