1 files changed, 139 insertions, 0 deletions
diff --git a/diffcore-pickaxe.c b/diffcore-pickaxe.c
new file mode 100644
index 0000000000..af9fffe6e8
--- /dev/null
+++ b/diffcore-pickaxe.c
@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2005 Junio C Hamano
+ */
+#include "cache.h"
+#include "diff.h"
+#include "diffcore.h"
+
+static unsigned int contains(struct diff_filespec *one,
+			     const char *needle, unsigned long len,
+			     regex_t *regexp)
+{
+	unsigned int cnt;
+	unsigned long offset, sz;
+	const char *data;
+	if (diff_populate_filespec(one, 0))
+		return 0;
+	if (!len)
+		return 0;
+
+	sz = one->size;
+	data = one->data;
+	cnt = 0;
+
+	if (regexp) {
+		regmatch_t regmatch;
+		int flags = 0;
+
+		while (*data && !regexec(regexp, data, 1, &regmatch, flags)) {
+			flags |= REG_NOTBOL;
+			data += regmatch.rm_so;
+			if (*data) data++;
+			cnt++;
+		}
+
+	} else { /* Classic exact string match */
+		/* Yes, I've heard of strstr(), but the thing is *data may
+		 * not be NUL terminated.  Sue me.
+		 */
+		for (offset = 0; offset + len <= sz; offset++) {
+			/* we count non-overlapping occurrences of needle */
+			if (!memcmp(needle, data + offset, len)) {
+				offset += len - 1;
+				cnt++;
+			}
+		}
+	}
+	diff_free_filespec_data(one);
+	return cnt;
+}
+
+void diffcore_pickaxe(const char *needle, int opts)
+{
+	struct diff_queue_struct *q = &diff_queued_diff;
+	unsigned long len = strlen(needle);
+	int i, has_changes;
+	regex_t regex, *regexp = NULL;
+	struct diff_queue_struct outq;
+	outq.queue = NULL;
+	outq.nr = outq.alloc = 0;
+
+	if (opts & DIFF_PICKAXE_REGEX) {
+		int err;
+		err = regcomp(&regex, needle, REG_EXTENDED | REG_NEWLINE);
+		if (err) {
+			/* The POSIX.2 people are surely sick */
+			char errbuf[1024];
+			regerror(err, &regex, errbuf, 1024);
+			regfree(&regex);
+			die("invalid pickaxe regex: %s", errbuf);
+		}
+		regexp = &regex;
+	}
+
+	if (opts & DIFF_PICKAXE_ALL) {
+		/* Showing the whole changeset if needle exists */
+		for (i = has_changes = 0; !has_changes && i < q->nr; i++) {
+			struct diff_filepair *p = q->queue[i];
+			if (!DIFF_FILE_VALID(p->one)) {
+				if (!DIFF_FILE_VALID(p->two))
+					continue; /* ignore unmerged */
+				/* created */
+				if (contains(p->two, needle, len, regexp))
+					has_changes++;
+			}
+			else if (!DIFF_FILE_VALID(p->two)) {
+				if (contains(p->one, needle, len, regexp))
+					has_changes++;
+			}
+			else if (!diff_unmodified_pair(p) &&
+				 contains(p->one, needle, len, regexp) !=
+				 contains(p->two, needle, len, regexp))
+				has_changes++;
+		}
+		if (has_changes)
+			return; /* 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];
+			has_changes = 0;
+			if (!DIFF_FILE_VALID(p->one)) {
+				if (!DIFF_FILE_VALID(p->two))
+					; /* ignore unmerged */
+				/* created */
+				else if (contains(p->two, needle, len, regexp))
+					has_changes = 1;
+			}
+			else if (!DIFF_FILE_VALID(p->two)) {
+				if (contains(p->one, needle, len, regexp))
+					has_changes = 1;
+			}
+			else if (!diff_unmodified_pair(p) &&
+				 contains(p->one, needle, len, regexp) !=
+				 contains(p->two, needle, len, regexp))
+				has_changes = 1;
+
+			if (has_changes)
+				diff_q(&outq, p);
+			else
+				diff_free_filepair(p);
+		}
+
+	if (opts & DIFF_PICKAXE_REGEX) {
+		regfree(&regex);
+	}
+
+	free(q->queue);
+	*q = outq;
+	return;
+}