Add basic diff view

Finally, xdiff is used to show per-file diffs via commit view.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

Makefile

@@ -6,7 +6,7 @@ CACHE_ROOT = /var/cache/cgit
 
 EXTLIBS = ../git/libgit.a ../git/xdiff/lib.a -lz -lcrypto
 OBJECTS = shared.o cache.o parsing.o html.o ui-shared.o ui-repolist.o \
-	ui-summary.o ui-log.o ui-view.c ui-tree.c ui-commit.c
+	ui-summary.o ui-log.o ui-view.c ui-tree.c ui-commit.c ui-diff.o
 
 CFLAGS += -Wall
 

cgit.c

@@ -36,6 +36,8 @@ static void cgit_print_repo_page(struct cacheitem *item)
 		cgit_print_commit(cgit_query_sha1);
 	} else if (!strcmp(cgit_query_page, "view")) {
 		cgit_print_view(cgit_query_sha1);
+	} else if (!strcmp(cgit_query_page, "diff")) {
+		cgit_print_diff(cgit_query_sha1, cgit_query_sha2);
 	}
 	cgit_print_docend();
 }

cgit.css

@@ -77,12 +77,18 @@ div.error {
 	font-weight: bold;
 	margin: 1em 2em;
 }
+div.ls-blob, div.ls-dir {
+	font-family: monospace;
+}
 div.ls-dir a {
 	font-weight: bold;
 }
 th.filesize, td.filesize {
 	text-align: right;
 }
+td.filesize {
+	font-family: monospace;
+}
 td.filemode {
 	font-family: monospace;
 }
@@ -154,6 +160,25 @@ table.diffstat td.summary {
 	color: #888;
 	padding-top: 0.5em;
 }
+
+table.diff td {
+	border: solid 1px black;
+	font-family: monospace;
+	white-space: pre;
+}
+
+table.diff td div.hunk {
+	background: #ccc;
+}
+
+table.diff td div.add {
+	color: green;
+}
+
+table.diff td div.del {
+	color: red;
+}
+
 .sha1 {
 	font-family: courier;
 	font-size: 90%;

cgit.h

@@ -57,6 +57,7 @@ extern char *cgit_query_repo;
 extern char *cgit_query_page;
 extern char *cgit_query_head;
 extern char *cgit_query_sha1;
+extern char *cgit_query_sha2;
 extern int   cgit_query_ofs;
 
 extern int htmlfd;
@@ -104,5 +105,6 @@ extern void cgit_print_log(const char *tip, int ofs, int cnt);
 extern void cgit_print_view(const char *hex);
 extern void cgit_print_tree(const char *hex);
 extern void cgit_print_commit(const char *hex);
+extern void cgit_print_diff(const char *old_hex, const char *new_hex);
 
 #endif /* CGIT_H */

shared.c

@@ -37,6 +37,7 @@ char *cgit_query_repo   = NULL;
 char *cgit_query_page   = NULL;
 char *cgit_query_head   = NULL;
 char *cgit_query_sha1   = NULL;
+char *cgit_query_sha2   = NULL;
 int   cgit_query_ofs    = 0;
 
 int htmlfd = 0;
@@ -83,6 +84,9 @@ void cgit_querystring_cb(const char *name, const char *value)
 	} else if (!strcmp(name, "id")) {
 		cgit_query_sha1 = xstrdup(value);
 		cgit_query_has_sha1 = 1;
+	} else if (!strcmp(name, "id2")) {
+		cgit_query_sha2 = xstrdup(value);
+		cgit_query_has_sha1 = 1;
 	} else if (!strcmp(name, "ofs")) {
 		cgit_query_ofs = atoi(value);
 	}

ui-diff.c

@@ -0,0 +1,131 @@
+/* ui-diff.c: show diff between two blobs
+ *
+ * Copyright (C) 2006 Lars Hjemli
+ *
+ * Licensed under GNU General Public License v2
+ *   (see COPYING for full license text)
+ */
+
+#include "cgit.h"
+#include "xdiff.h"
+
+char *diff_buffer;
+int diff_buffer_size;
+
+
+/*
+ * print a single line returned from xdiff
+ */
+static void print_line(char *line, int len)
+{
+	char *class = "ctx";
+	char c = line[len-1];
+
+	if (line[0] == '+')
+		class = "add";
+	else if (line[0] == '-')
+		class = "del";
+	else if (line[0] == '@')
+		class = "hunk";
+
+	htmlf("<div class='%s'>", class);
+	line[len-1] = '\0';
+	html_txt(line);
+	html("</div>");
+	line[len-1] = c;
+}
+
+/*
+ * Receive diff-buffers from xdiff and concatenate them as
+ * needed across multiple callbacks.
+ *
+ * This is basically a copy of xdiff-interface.c/xdiff_outf(),
+ * ripped from git and modified to use globals instead of
+ * a special callback-struct.
+ */
+int diff_cb(void *priv_, mmbuffer_t *mb, int nbuf)
+{
+	int i;
+
+	for (i = 0; i < nbuf; i++) {
+		if (mb[i].ptr[mb[i].size-1] != '\n') {
+			/* Incomplete line */
+			diff_buffer = xrealloc(diff_buffer,
+					       diff_buffer_size + mb[i].size);
+			memcpy(diff_buffer + diff_buffer_size,
+			       mb[i].ptr, mb[i].size);
+			diff_buffer_size += mb[i].size;
+			continue;
+		}
+
+		/* we have a complete line */
+		if (!diff_buffer) {
+			print_line(mb[i].ptr, mb[i].size);
+			continue;
+		}
+		diff_buffer = xrealloc(diff_buffer,
+				       diff_buffer_size + mb[i].size);
+		memcpy(diff_buffer + diff_buffer_size, mb[i].ptr, mb[i].size);
+		print_line(diff_buffer, diff_buffer_size + mb[i].size);
+		free(diff_buffer);
+		diff_buffer = NULL;
+		diff_buffer_size = 0;
+	}
+	if (diff_buffer) {
+		print_line(diff_buffer, diff_buffer_size);
+		free(diff_buffer);
+		diff_buffer = NULL;
+		diff_buffer_size = 0;
+	}
+	return 0;
+}
+
+static int load_mmfile(mmfile_t *file, const unsigned char *sha1)
+{
+	char type[20];
+
+	if (is_null_sha1(sha1)) {
+		file->ptr = (char *)"";
+		file->size = 0;
+	} else {
+		file->ptr = read_sha1_file(sha1, type, &file->size);
+	}
+	return 1;
+}
+
+static void run_diff(const unsigned char *sha1, const unsigned char *sha2)
+{
+	mmfile_t file1, file2;
+	xpparam_t diff_params;
+	xdemitconf_t emit_params;
+	xdemitcb_t emit_cb;
+
+	if (!load_mmfile(&file1, sha1) || !load_mmfile(&file2, sha2)) {
+		cgit_print_error("Unable to load files for diff");
+		return;
+	}
+
+	diff_params.flags = XDF_NEED_MINIMAL;
+
+	emit_params.ctxlen = 3;
+	emit_params.flags = XDL_EMIT_FUNCNAMES;
+
+	emit_cb.outf = diff_cb;
+
+	xdl_diff(&file1, &file2, &diff_params, &emit_params, &emit_cb);
+}
+
+
+
+void cgit_print_diff(const char *old_hex, const char *new_hex)
+{
+	unsigned char sha1[20], sha2[20];
+
+	get_sha1(old_hex, sha1);
+	get_sha1(new_hex, sha2);
+
+	html("<h2>diff</h2>\n");
+	html("<table class='diff'><tr><td>");
+	run_diff(sha1, sha2);
+	html("</td></tr></table>");
+}

xdiff.h

@@ -0,0 +1,105 @@
+/*
+ *  LibXDiff by Davide Libenzi ( File Differential Library )
+ *  Copyright (C) 2003  Davide Libenzi
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XDIFF_H)
+#define XDIFF_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* #ifdef __cplusplus */
+
+
+#define XDF_NEED_MINIMAL (1 << 1)
+#define XDF_IGNORE_WHITESPACE (1 << 2)
+#define XDF_IGNORE_WHITESPACE_CHANGE (1 << 3)
+#define XDF_WHITESPACE_FLAGS (XDF_IGNORE_WHITESPACE | XDF_IGNORE_WHITESPACE_CHANGE)
+
+#define XDL_PATCH_NORMAL '-'
+#define XDL_PATCH_REVERSE '+'
+#define XDL_PATCH_MODEMASK ((1 << 8) - 1)
+#define XDL_PATCH_IGNOREBSPACE (1 << 8)
+
+#define XDL_EMIT_FUNCNAMES (1 << 0)
+#define XDL_EMIT_COMMON (1 << 1)
+
+#define XDL_MMB_READONLY (1 << 0)
+
+#define XDL_MMF_ATOMIC (1 << 0)
+
+#define XDL_BDOP_INS 1
+#define XDL_BDOP_CPY 2
+#define XDL_BDOP_INSB 3
+
+#define XDL_MERGE_MINIMAL 0
+#define XDL_MERGE_EAGER 1
+#define XDL_MERGE_ZEALOUS 2
+
+typedef struct s_mmfile {
+	char *ptr;
+	long size;
+} mmfile_t;
+
+typedef struct s_mmbuffer {
+	char *ptr;
+	long size;
+} mmbuffer_t;
+
+typedef struct s_xpparam {
+	unsigned long flags;
+} xpparam_t;
+
+typedef struct s_xdemitcb {
+	void *priv;
+	int (*outf)(void *, mmbuffer_t *, int);
+} xdemitcb_t;
+
+typedef struct s_xdemitconf {
+	long ctxlen;
+	unsigned long flags;
+} xdemitconf_t;
+
+typedef struct s_bdiffparam {
+	long bsize;
+} bdiffparam_t;
+
+
+#define xdl_malloc(x) malloc(x)
+#define xdl_free(ptr) free(ptr)
+#define xdl_realloc(ptr,x) realloc(ptr,x)
+
+void *xdl_mmfile_first(mmfile_t *mmf, long *size);
+void *xdl_mmfile_next(mmfile_t *mmf, long *size);
+long xdl_mmfile_size(mmfile_t *mmf);
+
+int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+	     xdemitconf_t const *xecfg, xdemitcb_t *ecb);
+
+int xdl_merge(mmfile_t *orig, mmfile_t *mf1, const char *name1,
+		mmfile_t *mf2, const char *name2,
+		xpparam_t const *xpp, int level, mmbuffer_t *result);
+
+#ifdef __cplusplus
+}
+#endif /* #ifdef __cplusplus */
+
+#endif /* #if !defined(XDIFF_H) */
+