Merge branch 'rs/blame'

* rs/blame:
  blame: use xdi_diff_hunks(), get rid of struct patch
  add xdi_diff_hunks() for callers that only need hunk lengths
  Allow alternate "low-level" emit function from xdl_diff
  Always initialize xpparam_t to 0
  blame: inline get_patch()

11 files changed, 124 insertions, 155 deletions

diff --git a/builtin-blame.c b/builtin-blame.c
index 2457e71fc0..a0d60145f2 100644
--- a/builtin-blame.c
+++ b/builtin-blame.c
@@ -443,131 +443,6 @@ static struct origin *find_rename(struct scoreboard *sb,
 }
 
 /*
- * Parsing of patch chunks...
- */
-struct chunk {
-	/* line number in postimage; up to but not including this
-	 * line is the same as preimage
-	 */
-	int same;
-
-	/* preimage line number after this chunk */
-	int p_next;
-
-	/* postimage line number after this chunk */
-	int t_next;
-};
-
-struct patch {
-	struct chunk *chunks;
-	int num;
-};
-
-struct blame_diff_state {
-	struct patch *ret;
-	unsigned hunk_post_context;
-	unsigned hunk_in_pre_context : 1;
-};
-
-static void process_u_diff(void *state_, char *line, unsigned long len)
-{
-	struct blame_diff_state *state = state_;
-	struct chunk *chunk;
-	int off1, off2, len1, len2, num;
-
-	num = state->ret->num;
-	if (len < 4 || line[0] != '@' || line[1] != '@') {
-		if (state->hunk_in_pre_context && line[0] == ' ')
-			state->ret->chunks[num - 1].same++;
-		else {
-			state->hunk_in_pre_context = 0;
-			if (line[0] == ' ')
-				state->hunk_post_context++;
-			else
-				state->hunk_post_context = 0;
-		}
-		return;
-	}
-
-	if (num && state->hunk_post_context) {
-		chunk = &state->ret->chunks[num - 1];
-		chunk->p_next -= state->hunk_post_context;
-		chunk->t_next -= state->hunk_post_context;
-	}
-	state->ret->num = ++num;
-	state->ret->chunks = xrealloc(state->ret->chunks,
-				      sizeof(struct chunk) * num);
-	chunk = &state->ret->chunks[num - 1];
-	if (parse_hunk_header(line, len, &off1, &len1, &off2, &len2)) {
-		state->ret->num--;
-		return;
-	}
-
-	/* Line numbers in patch output are one based. */
-	off1--;
-	off2--;
-
-	chunk->same = len2 ? off2 : (off2 + 1);
-
-	chunk->p_next = off1 + (len1 ? len1 : 1);
-	chunk->t_next = chunk->same + len2;
-	state->hunk_in_pre_context = 1;
-	state->hunk_post_context = 0;
-}
-
-static struct patch *compare_buffer(mmfile_t *file_p, mmfile_t *file_o,
-				    int context)
-{
-	struct blame_diff_state state;
-	xpparam_t xpp;
-	xdemitconf_t xecfg;
-	xdemitcb_t ecb;
-
-	xpp.flags = xdl_opts;
-	memset(&xecfg, 0, sizeof(xecfg));
-	xecfg.ctxlen = context;
-	memset(&state, 0, sizeof(state));
-	state.ret = xmalloc(sizeof(struct patch));
-	state.ret->chunks = NULL;
-	state.ret->num = 0;
-
-	xdi_diff_outf(file_p, file_o, process_u_diff, &state, &xpp, &xecfg, &ecb);
-
-	if (state.ret->num) {
-		struct chunk *chunk;
-		chunk = &state.ret->chunks[state.ret->num - 1];
-		chunk->p_next -= state.hunk_post_context;
-		chunk->t_next -= state.hunk_post_context;
-	}
-	return state.ret;
-}
-
-/*
- * Run diff between two origins and grab the patch output, so that
- * we can pass blame for lines origin is currently suspected for
- * to its parent.
- */
-static struct patch *get_patch(struct origin *parent, struct origin *origin)
-{
-	mmfile_t file_p, file_o;
-	struct patch *patch;
-
-	fill_origin_blob(parent, &file_p);
-	fill_origin_blob(origin, &file_o);
-	if (!file_p.ptr || !file_o.ptr)
-		return NULL;
-	patch = compare_buffer(&file_p, &file_o, 0);
-	num_get_patch++;
-	return patch;
-}
-
-static void free_patch(struct patch *p)
-{
-	free(p->chunks);
-	free(p);
-}
-
-/*
  * Link in a new blame entry to the scoreboard.  Entries that cover the
  * same line range have been removed from the scoreboard previously.
  */
@@ -813,6 +688,22 @@ static void blame_chunk(struct scoreboard *sb,
 	}
 }
 
+struct blame_chunk_cb_data {
+	struct scoreboard *sb;
+	struct origin *target;
+	struct origin *parent;
+	long plno;
+	long tlno;
+};
+
+static void blame_chunk_cb(void *data, long same, long p_next, long t_next)
+{
+	struct blame_chunk_cb_data *d = data;
+	blame_chunk(d->sb, d->tlno, d->plno, same, d->target, d->parent);
+	d->plno = p_next;
+	d->tlno = t_next;
+}
+
 /*
  * We are looking at the origin 'target' and aiming to pass blame
  * for the lines it is suspected to its parent.  Run diff to find
@@ -822,26 +713,28 @@ static int pass_blame_to_parent(struct scoreboard *sb,
 				struct origin *target,
 				struct origin *parent)
 {
-	int i, last_in_target, plno, tlno;
-	struct patch *patch;
+	int last_in_target;
+	mmfile_t file_p, file_o;
+	struct blame_chunk_cb_data d = { sb, target, parent, 0, 0 };
+	xpparam_t xpp;
+	xdemitconf_t xecfg;
 
 	last_in_target = find_last_in_target(sb, target);
 	if (last_in_target < 0)
 		return 1; /* nothing remains for this target */
 
-	patch = get_patch(parent, target);
-	plno = tlno = 0;
-	for (i = 0; i < patch->num; i++) {
-		struct chunk *chunk = &patch->chunks[i];
+	fill_origin_blob(parent, &file_p);
+	fill_origin_blob(target, &file_o);
+	num_get_patch++;
 
-		blame_chunk(sb, tlno, plno, chunk->same, target, parent);
-		plno = chunk->p_next;
-		tlno = chunk->t_next;
-	}
+	memset(&xpp, 0, sizeof(xpp));
+	xpp.flags = xdl_opts;
+	memset(&xecfg, 0, sizeof(xecfg));
+	xecfg.ctxlen = 0;
+	xdi_diff_hunks(&file_p, &file_o, blame_chunk_cb, &d, &xpp, &xecfg);
 	/* The rest (i.e. anything after tlno) are the same as the parent */
-	blame_chunk(sb, tlno, plno, last_in_target, target, parent);
+	blame_chunk(sb, d.tlno, d.plno, last_in_target, target, parent);
 
-	free_patch(patch);
 	return 0;
 }
 
@@ -933,6 +826,23 @@ static void handle_split(struct scoreboard *sb,
 	}
 }
 
+struct handle_split_cb_data {
+	struct scoreboard *sb;
+	struct blame_entry *ent;
+	struct origin *parent;
+	struct blame_entry *split;
+	long plno;
+	long tlno;
+};
+
+static void handle_split_cb(void *data, long same, long p_next, long t_next)
+{
+	struct handle_split_cb_data *d = data;
+	handle_split(d->sb, d->ent, d->tlno, d->plno, same, d->parent, d->split);
+	d->plno = p_next;
+	d->tlno = t_next;
+}
+
 /*
  * Find the lines from parent that are the same as ent so that
  * we can pass blames to it.  file_p has the blob contents for
@@ -947,8 +857,9 @@ static void find_copy_in_blob(struct scoreboard *sb,
 	const char *cp;
 	int cnt;
 	mmfile_t file_o;
-	struct patch *patch;
-	int i, plno, tlno;
+	struct handle_split_cb_data d = { sb, ent, parent, split, 0, 0 };
+	xpparam_t xpp;
+	xdemitconf_t xecfg;
 
 	/*
 	 * Prepare mmfile that contains only the lines in ent.
@@ -963,24 +874,18 @@ static void find_copy_in_blob(struct scoreboard *sb,
 	}
 	file_o.size = cp - file_o.ptr;
 
-	patch = compare_buffer(file_p, &file_o, 1);
-
 	/*
 	 * file_o is a part of final image we are annotating.
 	 * file_p partially may match that image.
 	 */
+	memset(&xpp, 0, sizeof(xpp));
+	xpp.flags = xdl_opts;
+	memset(&xecfg, 0, sizeof(xecfg));
+	xecfg.ctxlen = 1;
 	memset(split, 0, sizeof(struct blame_entry [3]));
-	plno = tlno = 0;
-	for (i = 0; i < patch->num; i++) {
-		struct chunk *chunk = &patch->chunks[i];
-
-		handle_split(sb, ent, tlno, plno, chunk->same, parent, split);
-		plno = chunk->p_next;
-		tlno = chunk->t_next;
-	}
+	xdi_diff_hunks(file_p, &file_o, handle_split_cb, &d, &xpp, &xecfg);
 	/* remainder, if any, all match the preimage */
-	handle_split(sb, ent, tlno, plno, ent->num_lines, parent, split);
-	free_patch(patch);
+	handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split);
 }
 
 /*
diff --git a/builtin-rerere.c b/builtin-rerere.c
index dd4573fe8d..d4dec6b715 100644
--- a/builtin-rerere.c
+++ b/builtin-rerere.c
@@ -98,6 +98,7 @@ static int diff_two(const char *file1, const char *label1,
 
 	printf("--- a/%s\n+++ b/%s\n", label1, label2);
 	fflush(stdout);
+	memset(&xpp, 0, sizeof(xpp));
 	xpp.flags = XDF_NEED_MINIMAL;
 	memset(&xecfg, 0, sizeof(xecfg));
 	xecfg.ctxlen = 3;
diff --git a/combine-diff.c b/combine-diff.c
index 5aa1104d34..ec8df39bb0 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -213,6 +213,7 @@ static void combine_diff(const unsigned char *parent, mmfile_t *result_file,
 
 	parent_file.ptr = grab_blob(parent, &sz);
 	parent_file.size = sz;
+	memset(&xpp, 0, sizeof(xpp));
 	xpp.flags = XDF_NEED_MINIMAL;
 	memset(&xecfg, 0, sizeof(xecfg));
 	memset(&state, 0, sizeof(state));
diff --git a/diff.c b/diff.c
index e368fef14f..1918b73d53 100644
--- a/diff.c
+++ b/diff.c
@@ -400,6 +400,7 @@ static void diff_words_show(struct diff_words_data *diff_words)
 	mmfile_t minus, plus;
 	int i;
 
+	memset(&xpp, 0, sizeof(xpp));
 	memset(&xecfg, 0, sizeof(xecfg));
 	minus.size = diff_words->minus.text.size;
 	minus.ptr = xmalloc(minus.size);
@@ -1416,6 +1417,7 @@ static void builtin_diff(const char *name_a,
 		if (!pe)
 			pe = diff_funcname_pattern(two);
 
+		memset(&xpp, 0, sizeof(xpp));
 		memset(&xecfg, 0, sizeof(xecfg));
 		memset(&ecbdata, 0, sizeof(ecbdata));
 		ecbdata.label_path = lbl;
@@ -1489,6 +1491,7 @@ static void builtin_diffstat(const char *name_a, const char *name_b,
 		xdemitconf_t xecfg;
 		xdemitcb_t ecb;
 
+		memset(&xpp, 0, sizeof(xpp));
 		memset(&xecfg, 0, sizeof(xecfg));
 		xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
 		xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
@@ -1535,6 +1538,7 @@ static void builtin_checkdiff(const char *name_a, const char *name_b,
 		xdemitconf_t xecfg;
 		xdemitcb_t ecb;
 
+		memset(&xpp, 0, sizeof(xpp));
 		memset(&xecfg, 0, sizeof(xecfg));
 		xecfg.ctxlen = 1; /* at least one context line */
 		xpp.flags = XDF_NEED_MINIMAL;
@@ -2958,6 +2962,7 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
 		struct diff_filepair *p = q->queue[i];
 		int len1, len2;
 
+		memset(&xpp, 0, sizeof(xpp));
 		memset(&xecfg, 0, sizeof(xecfg));
 		if (p->status == 0)
 			return error("internal diff status error");
diff --git a/merge-file.c b/merge-file.c
index 2a939c9dd8..3120a95f78 100644
--- a/merge-file.c
+++ b/merge-file.c
@@ -61,6 +61,7 @@ static int generate_common_file(mmfile_t *res, mmfile_t *f1, mmfile_t *f2)
 	xdemitconf_t xecfg;
 	xdemitcb_t ecb;
 
+	memset(&xpp, 0, sizeof(xpp));
 	xpp.flags = XDF_NEED_MINIMAL;
 	memset(&xecfg, 0, sizeof(xecfg));
 	xecfg.ctxlen = 3;
diff --git a/xdiff-interface.c b/xdiff-interface.c
index 49e06af710..e8ef46d10d 100644
--- a/xdiff-interface.c
+++ b/xdiff-interface.c
@@ -1,6 +1,9 @@
 #include "cache.h"
 #include "xdiff-interface.h"
-#include "strbuf.h"
+#include "xdiff/xtypes.h"
+#include "xdiff/xdiffi.h"
+#include "xdiff/xemit.h"
+#include "xdiff/xmacros.h"
 
 struct xdiff_emit_state {
 	xdiff_emit_consume_fn consume;
@@ -153,6 +156,50 @@ int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
 	return ret;
 }
 
+struct xdiff_emit_hunk_state {
+	xdiff_emit_hunk_consume_fn consume;
+	void *consume_callback_data;
+};
+
+static int process_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
+			xdemitconf_t const *xecfg)
+{
+	long s1, s2, same, p_next, t_next;
+	xdchange_t *xch, *xche;
+	struct xdiff_emit_hunk_state *state = ecb->priv;
+	xdiff_emit_hunk_consume_fn fn = state->consume;
+	void *consume_callback_data = state->consume_callback_data;
+
+	for (xch = xscr; xch; xch = xche->next) {
+		xche = xdl_get_hunk(xch, xecfg);
+
+		s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
+		s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
+		same = s2 + XDL_MAX(xch->i1 - s1, 0);
+		p_next = xche->i1 + xche->chg1;
+		t_next = xche->i2 + xche->chg2;
+
+		fn(consume_callback_data, same, p_next, t_next);
+	}
+	return 0;
+}
+
+int xdi_diff_hunks(mmfile_t *mf1, mmfile_t *mf2,
+		   xdiff_emit_hunk_consume_fn fn, void *consume_callback_data,
+		   xpparam_t const *xpp, xdemitconf_t *xecfg)
+{
+	struct xdiff_emit_hunk_state state;
+	xdemitcb_t ecb;
+
+	memset(&state, 0, sizeof(state));
+	memset(&ecb, 0, sizeof(ecb));
+	state.consume = fn;
+	state.consume_callback_data = consume_callback_data;
+	xecfg->emit_func = (void (*)())process_diff;
+	ecb.priv = &state;
+	return xdi_diff(mf1, mf2, xpp, xecfg, &ecb);
+}
+
 int read_mmfile(mmfile_t *ptr, const char *filename)
 {
 	struct stat st;
diff --git a/xdiff-interface.h b/xdiff-interface.h
index eaf9cd3498..7352b9a9c2 100644
--- a/xdiff-interface.h
+++ b/xdiff-interface.h
@@ -4,12 +4,16 @@
 #include "xdiff/xdiff.h"
 
 typedef void (*xdiff_emit_consume_fn)(void *, char *, unsigned long);
+typedef void (*xdiff_emit_hunk_consume_fn)(void *, long, long, long);
 
 int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *ecb);
 int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
 		  xdiff_emit_consume_fn fn, void *consume_callback_data,
 		  xpparam_t const *xpp,
 		  xdemitconf_t const *xecfg, xdemitcb_t *xecb);
+int xdi_diff_hunks(mmfile_t *mf1, mmfile_t *mf2,
+		   xdiff_emit_hunk_consume_fn fn, void *consume_callback_data,
+		   xpparam_t const *xpp, xdemitconf_t *xecfg);
 int parse_hunk_header(char *line, int len,
 		      int *ob, int *on,
 		      int *nb, int *nn);
diff --git a/xdiff/xdiff.h b/xdiff/xdiff.h
index deebe02cd3..84fff583e2 100644
--- a/xdiff/xdiff.h
+++ b/xdiff/xdiff.h
@@ -87,6 +87,7 @@ typedef struct s_xdemitconf {
 	unsigned long flags;
 	find_func_t find_func;
 	void *find_func_priv;
+	void (*emit_func)();
 } xdemitconf_t;
 
 typedef struct s_bdiffparam {
diff --git a/xdiff/xdiffi.c b/xdiff/xdiffi.c
index 1bad8462fb..9d0324a38c 100644
--- a/xdiff/xdiffi.c
+++ b/xdiff/xdiffi.c
@@ -538,6 +538,8 @@ int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
 	     xdemitconf_t const *xecfg, xdemitcb_t *ecb) {
 	xdchange_t *xscr;
 	xdfenv_t xe;
+	emit_func_t ef = xecfg->emit_func ?
+		(emit_func_t)xecfg->emit_func : xdl_emit_diff;
 
 	if (xdl_do_diff(mf1, mf2, xpp, &xe) < 0) {
 
@@ -551,7 +553,7 @@ int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
 		return -1;
 	}
 	if (xscr) {
-		if (xdl_emit_diff(&xe, xscr, ecb, xecfg) < 0) {
+		if (ef(&xe, xscr, ecb, xecfg) < 0) {
 
 			xdl_free_script(xscr);
 			xdl_free_env(&xe);
diff --git a/xdiff/xemit.c b/xdiff/xemit.c
index d3d9c845c6..4625c1b421 100644
--- a/xdiff/xemit.c
+++ b/xdiff/xemit.c
@@ -27,7 +27,6 @@
 
 static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec);
 static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb);
-static xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg);
 
 
 
@@ -58,7 +57,7 @@ static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *
  * Starting at the passed change atom, find the latest change atom to be included
  * inside the differential hunk according to the specified configuration.
  */
-static xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg) {
+xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg) {
 	xdchange_t *xch, *xchp;
 
 	for (xchp = xscr, xch = xscr->next; xch; xchp = xch, xch = xch->next)
diff --git a/xdiff/xemit.h b/xdiff/xemit.h
index 440a7390fa..c2e2e83027 100644
--- a/xdiff/xemit.h
+++ b/xdiff/xemit.h
@@ -24,7 +24,10 @@
 #define XEMIT_H
 
 
+typedef int (*emit_func_t)(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
+			   xdemitconf_t const *xecfg);
 
+xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg);
 int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
 		  xdemitconf_t const *xecfg);