ui-tree: add support for source-filter option

This new option is used to specify an external command which will be
executed when displaying blob content in the tree view. Blob content
will be written to STDIN of the filter and STDOUT from the filter
will be included verbatim in the html output from cgit. The file name
of the blob will be passed as the only argument to the filter command.

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

4 files changed, 25 insertions, 4 deletions

diff --git a/cgit.c b/cgit.c
index 779a464..eb7b45d 100644
--- a/cgit.c
+++ b/cgit.c
@@ -91,24 +91,26 @@ void config_cb(const char *name, const char *value)
 	else if (!strcmp(name, "cache-dynamic-ttl"))
 		ctx.cfg.cache_dynamic_ttl = atoi(value);
 	else if (!strcmp(name, "embedded"))
 		ctx.cfg.embedded = atoi(value);
 	else if (!strcmp(name, "max-message-length"))
 		ctx.cfg.max_msg_len = atoi(value);
 	else if (!strcmp(name, "max-repodesc-length"))
 		ctx.cfg.max_repodesc_len = atoi(value);
 	else if (!strcmp(name, "max-repo-count"))
 		ctx.cfg.max_repo_count = atoi(value);
 	else if (!strcmp(name, "max-commit-count"))
 		ctx.cfg.max_commit_count = atoi(value);
+	else if (!strcmp(name, "source-filter"))
+		ctx.cfg.source_filter = new_filter(value, 1);
 	else if (!strcmp(name, "summary-log"))
 		ctx.cfg.summary_log = atoi(value);
 	else if (!strcmp(name, "summary-branches"))
 		ctx.cfg.summary_branches = atoi(value);
 	else if (!strcmp(name, "summary-tags"))
 		ctx.cfg.summary_tags = atoi(value);
 	else if (!strcmp(name, "agefile"))
 		ctx.cfg.agefile = xstrdup(value);
 	else if (!strcmp(name, "renamelimit"))
 		ctx.cfg.renamelimit = atoi(value);
 	else if (!strcmp(name, "robots"))
 		ctx.cfg.robots = xstrdup(value);
diff --git a/cgit.h b/cgit.h
index d0fff1f..f9cf0df 100644
--- a/cgit.h
+++ b/cgit.h
@@ -174,24 +174,25 @@ struct cgit_config {
 	int max_commit_count;
 	int max_lock_attempts;
 	int max_msg_len;
 	int max_repodesc_len;
 	int max_stats;
 	int nocache;
 	int noheader;
 	int renamelimit;
 	int snapshots;
 	int summary_branches;
 	int summary_log;
 	int summary_tags;
+	struct cgit_filter *source_filter;
 };
 
 struct cgit_page {
 	time_t modified;
 	time_t expires;
 	size_t size;
 	char *mimetype;
 	char *charset;
 	char *filename;
 	char *etag;
 	char *title;
 	int status;
diff --git a/cgitrc.5.txt b/cgitrc.5.txt
index a207fe0..d420ad4 100644
--- a/cgitrc.5.txt
+++ b/cgitrc.5.txt
@@ -189,24 +189,32 @@ root-title::
 	"Git Repository Browser".
 
 snapshots::
 	Text which specifies the default (and allowed) set of snapshot formats
 	supported by cgit. The value is a space-separated list of zero or more
 	of the following values:
 		"tar"		uncompressed tar-file
 		"tar.gz"	gzip-compressed tar-file
 		"tar.bz2"	bzip-compressed tar-file
 		"zip"		zip-file
 	Default value: none.
 
+source-filter::
+	Specifies a command which will be invoked to format plaintext blobs
+	in the tree view. The command will get the blob content on its STDIN
+	and the name of the blob as its only command line argument. The STDOUT
+	from the command will be included verbatim as the blob contents, i.e.
+	this can be used to implement e.g. syntax highlighting. Default value:
+	none.
+
 summary-branches::
 	Specifies the number of branches to display in the repository "summary"
 	view. Default value: "10".
 
 summary-log::
 	Specifies the number of log entries to display in the repository
 	"summary" view. Default value: "10".
 
 summary-tags::
 	Specifies the number of tags to display in the repository "summary"
 	view. Default value: "10".
 
diff --git a/ui-tree.c b/ui-tree.c
index 553dbaa..816e121 100644
--- a/ui-tree.c
+++ b/ui-tree.c
@@ -6,31 +6,41 @@
  *   (see COPYING for full license text)
  */
 
 #include <ctype.h>
 #include "cgit.h"
 #include "html.h"
 #include "ui-shared.h"
 
 char *curr_rev;
 char *match_path;
 int header = 0;
 
-static void print_text_buffer(char *buf, unsigned long size)
+static void print_text_buffer(const char *name, char *buf, unsigned long size)
 {
 	unsigned long lineno, idx;
 	const char *numberfmt =
 		"<a class='no' id='n%1$d' name='n%1$d' href='#n%1$d'>%1$d</a>\n";
 
 	html("<table summary='blob content' class='blob'>\n");
+	if (ctx.cfg.source_filter) {
+		html("<tr><td class='lines'><pre><code>");
+		ctx.cfg.source_filter->argv[1] = xstrdup(name);
+		cgit_open_filter(ctx.cfg.source_filter);
+		write(STDOUT_FILENO, buf, size);
+		cgit_close_filter(ctx.cfg.source_filter);
+		html("</code></pre></td></tr></table>\n");
+		return;
+	}
+
 	html("<tr><td class='linenumbers'><pre>");
 	idx = 0;
 	lineno = 0;
 
 	if (size) {
 		htmlf(numberfmt, ++lineno);
 		while(idx < size - 1) { // skip absolute last newline
 			if (buf[idx] == '\n')
 				htmlf(numberfmt, ++lineno);
 			idx++;
 		}
 	}
@@ -56,25 +66,25 @@ static void print_binary_buffer(char *buf, unsigned long size)
 			      idx == 16 ? 4 : 1, "",
 			      buf[idx] & 0xff);
 		html(" </td><td class='hex'>");
 		for (idx = 0; idx < ROWLEN && ofs + idx < size; idx++)
 			ascii[idx] = isgraph(buf[idx]) ? buf[idx] : '.';
 		ascii[idx] = '\0';
 		html_txt(ascii);
 		html("</td></tr>\n");
 	}
 	html("</table>\n");
 }
 
-static void print_object(const unsigned char *sha1, char *path)
+static void print_object(const unsigned char *sha1, char *path, const char *basename)
 {
 	enum object_type type;
 	char *buf;
 	unsigned long size;
 
 	type = sha1_object_info(sha1, &size);
 	if (type == OBJ_BAD) {
 		cgit_print_error(fmt("Bad object name: %s",
 				     sha1_to_hex(sha1)));
 		return;
 	}
 
@@ -84,25 +94,25 @@ static void print_object(const unsigned char *sha1, char *path)
 				     sha1_to_hex(sha1)));
 		return;
 	}
 
 	html(" (");
 	cgit_plain_link("plain", NULL, NULL, ctx.qry.head,
 		        curr_rev, path);
 	htmlf(")<br/>blob: %s\n", sha1_to_hex(sha1));
 
 	if (buffer_is_binary(buf, size))
 		print_binary_buffer(buf, size);
 	else
-		print_text_buffer(buf, size);
+		print_text_buffer(basename, buf, size);
 }
 
 
 static int ls_item(const unsigned char *sha1, const char *base, int baselen,
 		   const char *pathname, unsigned int mode, int stage,
 		   void *cbdata)
 {
 	char *name;
 	char *fullpath;
 	enum object_type type;
 	unsigned long size = 0;
 
@@ -204,25 +214,25 @@ static int walk_tree(const unsigned char *sha1, const char *base, int baselen,
 		html("/");
 		cgit_tree_link(xstrdup(pathname), NULL, NULL, ctx.qry.head,
 			       curr_rev, buffer);
 
 		if (strcmp(match_path, buffer))
 			return READ_TREE_RECURSIVE;
 
 		if (S_ISDIR(mode)) {
 			state = 1;
 			ls_head();
 			return READ_TREE_RECURSIVE;
 		} else {
-			print_object(sha1, buffer);
+			print_object(sha1, buffer, pathname);
 			return 0;
 		}
 	}
 	ls_item(sha1, base, baselen, pathname, mode, stage, NULL);
 	return 0;
 }
 
 
 /*
  * Show a tree or a blob
  *   rev:  the commit pointing at the root tree object
  *   path: path to tree or blob