Add basic diff view

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

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

7 files changed, 270 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 58a583b..4aa7afe 100644
--- a/Makefile
+++ b/Makefile
@@ -7,5 +7,5 @@ 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
diff --git a/cgit.c b/cgit.c
index 372b436..ac43441 100644
--- a/cgit.c
+++ b/cgit.c
@@ -37,4 +37,6 @@ static void cgit_print_repo_page(struct cacheitem *item)
         } 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();
diff --git a/cgit.css b/cgit.css
index 5f01926..7b8e468 100644
--- a/cgit.css
+++ b/cgit.css
@@ -78,4 +78,7 @@ div.error {
         margin: 1em 2em;
 }
+div.ls-blob, div.ls-dir {
+        font-family: monospace;
+}
 div.ls-dir a {
         font-weight: bold;
@@ -84,4 +87,7 @@ th.filesize, td.filesize {
         text-align: right;
 }
+td.filesize {
+        font-family: monospace;
+}
 td.filemode {
         font-family: monospace;
@@ -155,4 +161,23 @@ table.diffstat td.summary {
         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;
diff --git a/cgit.h b/cgit.h
index 37584d6..bba2d6c 100644
--- a/cgit.h
+++ b/cgit.h
@@ -58,4 +58,5 @@ 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;
 
@@ -105,4 +106,5 @@ 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 */
diff --git a/shared.c b/shared.c
index b576df8..762eb38 100644
--- a/shared.c
+++ b/shared.c
@@ -38,4 +38,5 @@ 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;
 
@@ -84,4 +85,7 @@ void cgit_querystring_cb(const char *name, const char *value)
                 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);
diff --git a/ui-diff.c b/ui-diff.c
new file mode 100644
index 0000000..0bd9ade
--- a/dev/null
+++ b/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>");
+}
diff --git a/xdiff.h b/xdiff.h
new file mode 100644
index 0000000..fa409d5
--- a/dev/null
+++ b/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) */
+