1 files changed, 238 insertions, 0 deletions
diff --git a/diffcore-pickaxe.c b/diffcore-pickaxe.c
new file mode 100644
index 0000000000..185f86b284
--- /dev/null
+++ b/diffcore-pickaxe.c
@@ -0,0 +1,238 @@
+/*
+ * Copyright (C) 2005 Junio C Hamano
+ * Copyright (C) 2010 Google Inc.
+ */
+#include "cache.h"
+#include "diff.h"
+#include "diffcore.h"
+#include "xdiff-interface.h"
+#include "kwset.h"
+
+typedef int (*pickaxe_fn)(mmfile_t *one, mmfile_t *two,
+			  struct diff_options *o,
+			  regex_t *regexp, kwset_t kws);
+
+struct diffgrep_cb {
+	regex_t *regexp;
+	int hit;
+};
+
+static void diffgrep_consume(void *priv, char *line, unsigned long len)
+{
+	struct diffgrep_cb *data = priv;
+	regmatch_t regmatch;
+	int hold;
+
+	if (line[0] != '+' && line[0] != '-')
+		return;
+	if (data->hit)
+		/*
+		 * NEEDSWORK: we should have a way to terminate the
+		 * caller early.
+		 */
+		return;
+	/* Yuck -- line ought to be "const char *"! */
+	hold = line[len];
+	line[len] = '\0';
+	data->hit = !regexec(data->regexp, line + 1, 1, &regmatch, 0);
+	line[len] = hold;
+}
+
+static int diff_grep(mmfile_t *one, mmfile_t *two,
+		     struct diff_options *o,
+		     regex_t *regexp, kwset_t kws)
+{
+	regmatch_t regmatch;
+	struct diffgrep_cb ecbdata;
+	xpparam_t xpp;
+	xdemitconf_t xecfg;
+
+	if (!one)
+		return !regexec(regexp, two->ptr, 1, &regmatch, 0);
+	if (!two)
+		return !regexec(regexp, one->ptr, 1, &regmatch, 0);
+
+	/*
+	 * We have both sides; need to run textual diff and see if
+	 * the pattern appears on added/deleted lines.
+	 */
+	memset(&xpp, 0, sizeof(xpp));
+	memset(&xecfg, 0, sizeof(xecfg));
+	ecbdata.regexp = regexp;
+	ecbdata.hit = 0;
+	xecfg.ctxlen = o->context;
+	xecfg.interhunkctxlen = o->interhunkcontext;
+	xdi_diff_outf(one, two, diffgrep_consume, &ecbdata,
+		      &xpp, &xecfg);
+	return ecbdata.hit;
+}
+
+static unsigned int contains(mmfile_t *mf, regex_t *regexp, kwset_t kws)
+{
+	unsigned int cnt;
+	unsigned long sz;
+	const char *data;
+
+	sz = mf->size;
+	data = mf->ptr;
+	cnt = 0;
+
+	if (regexp) {
+		regmatch_t regmatch;
+		int flags = 0;
+
+		assert(data[sz] == '\0');
+		while (*data && !regexec(regexp, data, 1, &regmatch, flags)) {
+			flags |= REG_NOTBOL;
+			data += regmatch.rm_eo;
+			if (*data && regmatch.rm_so == regmatch.rm_eo)
+				data++;
+			cnt++;
+		}
+
+	} else { /* Classic exact string match */
+		while (sz) {
+			struct kwsmatch kwsm;
+			size_t offset = kwsexec(kws, data, sz, &kwsm);
+			if (offset == -1)
+				break;
+			sz -= offset + kwsm.size[0];
+			data += offset + kwsm.size[0];
+			cnt++;
+		}
+	}
+	return cnt;
+}
+
+static int has_changes(mmfile_t *one, mmfile_t *two,
+		       struct diff_options *o,
+		       regex_t *regexp, kwset_t kws)
+{
+	unsigned int one_contains = one ? contains(one, regexp, kws) : 0;
+	unsigned int two_contains = two ? contains(two, regexp, kws) : 0;
+	return one_contains != two_contains;
+}
+
+static int pickaxe_match(struct diff_filepair *p, struct diff_options *o,
+			 regex_t *regexp, kwset_t kws, pickaxe_fn fn)
+{
+	struct userdiff_driver *textconv_one = NULL;
+	struct userdiff_driver *textconv_two = NULL;
+	mmfile_t mf1, mf2;
+	int ret;
+
+	if (!o->pickaxe[0])
+		return 0;
+
+	/* ignore unmerged */
+	if (!DIFF_FILE_VALID(p->one) && !DIFF_FILE_VALID(p->two))
+		return 0;
+
+	if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
+		textconv_one = get_textconv(p->one);
+		textconv_two = get_textconv(p->two);
+	}
+
+	/*
+	 * If we have an unmodified pair, we know that the count will be the
+	 * same and don't even have to load the blobs. Unless textconv is in
+	 * play, _and_ we are using two different textconv filters (e.g.,
+	 * because a pair is an exact rename with different textconv attributes
+	 * for each side, which might generate different content).
+	 */
+	if (textconv_one == textconv_two && diff_unmodified_pair(p))
+		return 0;
+
+	mf1.size = fill_textconv(textconv_one, p->one, &mf1.ptr);
+	mf2.size = fill_textconv(textconv_two, p->two, &mf2.ptr);
+
+	ret = fn(DIFF_FILE_VALID(p->one) ? &mf1 : NULL,
+		 DIFF_FILE_VALID(p->two) ? &mf2 : NULL,
+		 o, regexp, kws);
+
+	if (textconv_one)
+		free(mf1.ptr);
+	if (textconv_two)
+		free(mf2.ptr);
+	diff_free_filespec_data(p->one);
+	diff_free_filespec_data(p->two);
+
+	return ret;
+}
+
+static void pickaxe(struct diff_queue_struct *q, struct diff_options *o,
+		    regex_t *regexp, kwset_t kws, pickaxe_fn fn)
+{
+	int i;
+	struct diff_queue_struct outq;
+
+	DIFF_QUEUE_CLEAR(&outq);
+
+	if (o->pickaxe_opts & DIFF_PICKAXE_ALL) {
+		/* Showing the whole changeset if needle exists */
+		for (i = 0; i < q->nr; i++) {
+			struct diff_filepair *p = q->queue[i];
+			if (pickaxe_match(p, o, regexp, kws, fn))
+				return; /* do not munge the queue */
+		}
+
+		/*
+		 * Otherwise we will clear the whole queue by copying
+		 * the empty outq at the end of this function, but
+		 * first clear the current entries in the queue.
+		 */
+		for (i = 0; i < q->nr; i++)
+			diff_free_filepair(q->queue[i]);
+	} else {
+		/* Showing only the filepairs that has the needle */
+		for (i = 0; i < q->nr; i++) {
+			struct diff_filepair *p = q->queue[i];
+			if (pickaxe_match(p, o, regexp, kws, fn))
+				diff_q(&outq, p);
+			else
+				diff_free_filepair(p);
+		}
+	}
+
+	free(q->queue);
+	*q = outq;
+}
+
+void diffcore_pickaxe(struct diff_options *o)
+{
+	const char *needle = o->pickaxe;
+	int opts = o->pickaxe_opts;
+	regex_t regex, *regexp = NULL;
+	kwset_t kws = NULL;
+
+	if (opts & (DIFF_PICKAXE_REGEX | DIFF_PICKAXE_KIND_G)) {
+		int err;
+		int cflags = REG_EXTENDED | REG_NEWLINE;
+		if (DIFF_OPT_TST(o, PICKAXE_IGNORE_CASE))
+			cflags |= REG_ICASE;
+		err = regcomp(&regex, needle, cflags);
+		if (err) {
+			/* The POSIX.2 people are surely sick */
+			char errbuf[1024];
+			regerror(err, &regex, errbuf, 1024);
+			regfree(&regex);
+			die("invalid regex: %s", errbuf);
+		}
+		regexp = &regex;
+	} else {
+		kws = kwsalloc(DIFF_OPT_TST(o, PICKAXE_IGNORE_CASE)
+			       ? tolower_trans_tbl : NULL);
+		kwsincr(kws, needle, strlen(needle));
+		kwsprep(kws);
+	}
+
+	/* Might want to warn when both S and G are on; I don't care... */
+	pickaxe(&diff_queued_diff, o, regexp, kws,
+		(opts & DIFF_PICKAXE_KIND_G) ? diff_grep : has_changes);
+
+	if (regexp)
+		regfree(regexp);
+	else
+		kwsfree(kws);
+	return;
+}