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authorJunio C Hamano <junkio@cox.net>2005-05-21 02:40:01 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-05-21 09:58:03 -0700
commit52e9578985fb636ec1d3f6cf794fdadd5ec896fc (patch)
treebb22f522116f5d8e6ae677b7a4660e959c052fc2 /diffcore-pickaxe.c
parent427dcb4bca49117664d9428fd4e86483f516d703 (diff)
downloadgit-52e9578985fb636ec1d3f6cf794fdadd5ec896fc.tar.gz
git-52e9578985fb636ec1d3f6cf794fdadd5ec896fc.tar.xz
[PATCH] Introducing software archaeologist's tool "pickaxe".
This steals the "pickaxe" feature from JIT and make it available to the bare Plumbing layer. From the command line, the user gives a string he is intersted in. Using the diff-core infrastructure previously introduced, it filters the differences to limit the output only to the diffs between <src> and <dst> where the string appears only in one but not in the other. For example: $ ./git-rev-list HEAD | ./git-diff-tree -Sdiff-tree-helper --stdin -M would show the diffs that touch the string "diff-tree-helper". In real software-archaeologist application, you would typically look for a few to several lines of code and see where that code came from. The "pickaxe" module runs after "rename/copy detection" module, so it even crosses the file rename boundary, as the above example demonstrates. Signed-off-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'diffcore-pickaxe.c')
-rw-r--r--diffcore-pickaxe.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/diffcore-pickaxe.c b/diffcore-pickaxe.c
new file mode 100644
index 000000000..ee22e36ab
--- /dev/null
+++ b/diffcore-pickaxe.c
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2005 Junio C Hamano
+ */
+#include "cache.h"
+#include "diff.h"
+#include "diffcore.h"
+#include "delta.h"
+
+static int contains(struct diff_filespec *one,
+ const char *needle, unsigned long len)
+{
+ unsigned long offset, sz;
+ const char *data;
+ if (diff_populate_filespec(one))
+ return 0;
+ sz = one->size;
+ data = one->data;
+ for (offset = 0; offset + len <= sz; offset++)
+ if (!strncmp(needle, data + offset, len))
+ return 1;
+ return 0;
+}
+
+void diff_pickaxe(struct diff_queue_struct *q, const char *needle)
+{
+ unsigned long len = strlen(needle);
+ int i;
+ struct diff_queue_struct outq;
+ outq.queue = NULL;
+ outq.nr = outq.alloc = 0;
+
+ for (i = 0; i < q->nr; i++) {
+ struct diff_filepair *p = q->queue[i];
+ if (!p->one->file_valid) {
+ if (!p->two->file_valid)
+ continue; /* ignore nonsense */
+ /* created */
+ if (contains(p->two, needle, len))
+ diff_queue(&outq, p->one, p->two);
+ }
+ else if (!p->two->file_valid) {
+ if (contains(p->one, needle, len))
+ diff_queue(&outq, p->one, p->two);
+ }
+ else if (contains(p->one, needle, len) !=
+ contains(p->two, needle, len))
+ diff_queue(&outq, p->one, p->two);
+ }
+ for (i = 0; i < q->nr; i++) {
+ struct diff_filepair *p = q->queue[i];
+ free(p);
+ }
+ free(q->queue);
+ *q = outq;
+ return;
+}