Add command dispatcher

This simplifies the code in cgit.c and makes it easier to extend cgit with
new pages/commands.

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

7 files changed, 169 insertions, 110 deletions

diff --git a/Makefile b/Makefile
index 7102908..d9ff7d8 100644
--- a/Makefile
+++ b/Makefile
@@ -7,25 +7,25 @@ SHA1_HEADER = <openssl/sha.h>
 GIT_VER = 1.5.4.1
 GIT_URL = http://www.kernel.org/pub/software/scm/git/git-$(GIT_VER).tar.bz2
 
 #
 # Let the user override the above settings.
 #
 -include cgit.conf
 
 
 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-tree.o ui-commit.o ui-diff.o \
-	ui-snapshot.o ui-blob.o ui-tag.o ui-refs.o ui-patch.o
+	ui-snapshot.o ui-blob.o ui-tag.o ui-refs.o ui-patch.o cmd.o
 
 
 ifdef NEEDS_LIBICONV
 	EXTLIBS += -liconv
 endif
 
 
 .PHONY: all git test install clean distclean emptycache force-version get-git
 
 all: cgit git
 
 VERSION: force-version
diff --git a/cgit.c b/cgit.c
index a83f0be..79e0e43 100644
--- a/cgit.c
+++ b/cgit.c
@@ -72,156 +72,126 @@ char *find_default_branch(struct cgit_repo *repo)
 	struct refmatch info;
 
 	info.req_ref = repo->defbranch;
 	info.first_ref = NULL;
 	info.match = 0;
 	for_each_branch_ref(find_current_ref, &info);
 	if (info.match)
 		return info.req_ref;
 	else
 		return info.first_ref;
 }
 
-static void cgit_print_repo_page()
+static int prepare_repo_cmd(struct cgit_context *ctx)
 {
 	char *tmp;
-	int show_search;
 	unsigned char sha1[20];
 	int nongit = 0;
 
-	setenv("GIT_DIR", ctx.repo->path, 1);
+	setenv("GIT_DIR", ctx->repo->path, 1);
 	setup_git_directory_gently(&nongit);
 	if (nongit) {
-		ctx.page.title = fmt("%s - %s", ctx.cfg.root_title,
-				     "config error");
-		tmp = fmt("Not a git repository: '%s'", ctx.repo->path);
-		ctx.repo = NULL;
-		cgit_print_http_headers(&ctx);
-		cgit_print_docstart(&ctx);
-		cgit_print_pageheader(&ctx);
+		ctx->page.title = fmt("%s - %s", ctx->cfg.root_title,
+				      "config error");
+		tmp = fmt("Not a git repository: '%s'", ctx->repo->path);
+		ctx->repo = NULL;
+		cgit_print_http_headers(ctx);
+		cgit_print_docstart(ctx);
+		cgit_print_pageheader(ctx);
 		cgit_print_error(tmp);
 		cgit_print_docend();
-		return;
+		return 1;
 	}
+	ctx->page.title = fmt("%s - %s", ctx->repo->name, ctx->repo->desc);
 
-	ctx.page.title = fmt("%s - %s", ctx.repo->name, ctx.repo->desc);
-	show_search = 0;
-
-	if (!ctx.qry.head) {
-		ctx.qry.head = xstrdup(find_default_branch(ctx.repo));
-		ctx.repo->defbranch = ctx.qry.head;
+	if (!ctx->qry.head) {
+		ctx->qry.head = xstrdup(find_default_branch(ctx->repo));
+		ctx->repo->defbranch = ctx->qry.head;
 	}
 
-	if (!ctx.qry.head) {
-		cgit_print_http_headers(&ctx);
-		cgit_print_docstart(&ctx);
-		cgit_print_pageheader(&ctx);
+	if (!ctx->qry.head) {
+		cgit_print_http_headers(ctx);
+		cgit_print_docstart(ctx);
+		cgit_print_pageheader(ctx);
 		cgit_print_error("Repository seems to be empty");
 		cgit_print_docend();
-		return;
+		return 1;
 	}
 
-	if (get_sha1(ctx.qry.head, sha1)) {
-		tmp = xstrdup(ctx.qry.head);
-		ctx.qry.head = ctx.repo->defbranch;
-		cgit_print_http_headers(&ctx);
-		cgit_print_docstart(&ctx);
-		cgit_print_pageheader(&ctx);
+	if (get_sha1(ctx->qry.head, sha1)) {
+		tmp = xstrdup(ctx->qry.head);
+		ctx->qry.head = ctx->repo->defbranch;
+		cgit_print_http_headers(ctx);
+		cgit_print_docstart(ctx);
+		cgit_print_pageheader(ctx);
 		cgit_print_error(fmt("Invalid branch: %s", tmp));
 		cgit_print_docend();
-		return;
+		return 1;
 	}
+	return 0;
+}
 
-	if ((cgit_cmd == CMD_SNAPSHOT) && ctx.repo->snapshots) {
-		cgit_print_snapshot(ctx.qry.head, ctx.qry.sha1,
-				    cgit_repobasename(ctx.repo->url),
-				    ctx.qry.path,
-				    ctx.repo->snapshots );
+static void process_request(struct cgit_context *ctx)
+{
+	struct cgit_cmd *cmd;
+
+	cmd = cgit_get_cmd(ctx);
+	if (!cmd) {
+		ctx->page.title = "cgit error";
+		ctx->repo = NULL;
+		cgit_print_http_headers(ctx);
+		cgit_print_docstart(ctx);
+		cgit_print_pageheader(ctx);
+		cgit_print_error("Invalid request");
+		cgit_print_docend();
 		return;
 	}
 
-	if (cgit_cmd == CMD_PATCH) {
-		cgit_print_patch(ctx.qry.sha1);
+	if (cmd->want_repo && prepare_repo_cmd(ctx))
 		return;
-	}
 
-	if (cgit_cmd == CMD_BLOB) {
-		cgit_print_blob(ctx.qry.sha1, ctx.qry.path);
-		return;
+	if (cmd->want_layout) {
+		cgit_print_http_headers(ctx);
+		cgit_print_docstart(ctx);
+		cgit_print_pageheader(ctx);
 	}
 
-	show_search = (cgit_cmd == CMD_LOG);
-	cgit_print_http_headers(&ctx);
-	cgit_print_docstart(&ctx);
-	if (!cgit_cmd) {
-		cgit_print_pageheader(&ctx);
-		cgit_print_summary();
-		cgit_print_docend();
-		return;
-	}
+	cmd->fn(ctx);
 
-	cgit_print_pageheader(&ctx);
-
-	switch(cgit_cmd) {
-	case CMD_LOG:
-		cgit_print_log(ctx.qry.sha1, ctx.qry.ofs,
-			       ctx.cfg.max_commit_count, ctx.qry.grep, ctx.qry.search,
-			       ctx.qry.path, 1);
-		break;
-	case CMD_TREE:
-		cgit_print_tree(ctx.qry.sha1, ctx.qry.path);
-		break;
-	case CMD_COMMIT:
-		cgit_print_commit(ctx.qry.sha1);
-		break;
-	case CMD_REFS:
-		cgit_print_refs();
-		break;
-	case CMD_TAG:
-		cgit_print_tag(ctx.qry.sha1);
-		break;
-	case CMD_DIFF:
-		cgit_print_diff(ctx.qry.sha1, ctx.qry.sha2, ctx.qry.path);
-		break;
-	default:
-		cgit_print_error("Invalid request");
-	}
-	cgit_print_docend();
+	if (cmd->want_layout)
+		cgit_print_docend();
 }
 
 static long ttl_seconds(long ttl)
 {
 	if (ttl<0)
 		return 60 * 60 * 24 * 365;
 	else
 		return ttl * 60;
 }
 
 static void cgit_fill_cache(struct cacheitem *item, int use_cache)
 {
 	int stdout2;
 
 	if (use_cache) {
 		stdout2 = chk_positive(dup(STDOUT_FILENO),
 				       "Preserving STDOUT");
 		chk_zero(close(STDOUT_FILENO), "Closing STDOUT");
 		chk_positive(dup2(item->fd, STDOUT_FILENO), "Dup2(cachefile)");
 	}
 
 	ctx.page.modified = time(NULL);
 	ctx.page.expires = ctx.page.modified + ttl_seconds(item->ttl);
-	if (ctx.repo)
-		cgit_print_repo_page();
-	else
-		cgit_print_repolist();
+	process_request(&ctx);
 
 	if (use_cache) {
 		chk_zero(close(STDOUT_FILENO), "Close redirected STDOUT");
 		chk_positive(dup2(stdout2, STDOUT_FILENO),
 			     "Restoring original STDOUT");
 		chk_zero(close(stdout2), "Closing temporary STDOUT");
 	}
 }
 
 static void cgit_check_cache(struct cacheitem *item)
 {
 	int i = 0;
diff --git a/cgit.h b/cgit.h
index 40e2d40..295441b 100644
--- a/cgit.h
+++ b/cgit.h
@@ -11,37 +11,24 @@
 #include <tag.h>
 #include <diff.h>
 #include <diffcore.h>
 #include <refs.h>
 #include <revision.h>
 #include <log-tree.h>
 #include <archive.h>
 #include <xdiff/xdiff.h>
 #include <utf8.h>
 
 
 /*
- * The valid cgit repo-commands
- */
-#define CMD_LOG      1
-#define CMD_COMMIT   2
-#define CMD_DIFF     3
-#define CMD_TREE     4
-#define CMD_BLOB     5
-#define CMD_SNAPSHOT 6
-#define CMD_TAG      7
-#define CMD_REFS     8
-#define CMD_PATCH    9
-
-/*
  * Dateformats used on misc. pages
  */
 #define FMT_LONGDATE "%Y-%m-%d %H:%M:%S"
 #define FMT_SHORTDATE "%Y-%m-%d"
 
 
 /*
  * Limits used for relative dates
  */
 #define TM_MIN    60
 #define TM_HOUR  (TM_MIN * 60)
 #define TM_DAY   (TM_HOUR * 24)
@@ -188,25 +175,24 @@ struct cgit_context {
 	struct cgit_config cfg;
 	struct cgit_repo *repo;
 	struct cgit_page page;
 };
 
 extern const char *cgit_version;
 
 extern struct cgit_repolist cgit_repolist;
 extern struct cgit_context ctx;
 extern int cgit_cmd;
 
 extern void cgit_prepare_context(struct cgit_context *ctx);
-extern int cgit_get_cmd_index(const char *cmd);
 extern struct cgit_repo *cgit_get_repoinfo(const char *url);
 extern void cgit_global_config_cb(const char *name, const char *value);
 extern void cgit_repo_config_cb(const char *name, const char *value);
 extern void cgit_querystring_cb(const char *name, const char *value);
 
 extern int chk_zero(int result, char *msg);
 extern int chk_positive(int result, char *msg);
 extern int chk_non_negative(int result, char *msg);
 
 extern int hextoint(char c);
 extern char *trim_end(const char *str, char c);
 extern char *strlpart(char *txt, int maxlen);
diff --git a/cmd.c b/cmd.c
new file mode 100644
index 0000000..489a11c
--- a/dev/null
+++ b/cmd.c
@@ -0,0 +1,101 @@
+/* cmd.c: the cgit command dispatcher
+ *
+ * Copyright (C) 2008 Lars Hjemli
+ *
+ * Licensed under GNU General Public License v2
+ *   (see COPYING for full license text)
+ */
+
+#include "cgit.h"
+#include "cmd.h"
+
+static void blob_fn(struct cgit_context *ctx)
+{
+	cgit_print_blob(ctx->qry.sha1, ctx->qry.path);
+}
+
+static void commit_fn(struct cgit_context *ctx)
+{
+	cgit_print_commit(ctx->qry.sha1);
+}
+
+static void diff_fn(struct cgit_context *ctx)
+{
+	cgit_print_diff(ctx->qry.sha1, ctx->qry.sha2, ctx->qry.path);
+}
+
+static void repolist_fn(struct cgit_context *ctx)
+{
+	cgit_print_repolist();
+}
+
+static void log_fn(struct cgit_context *ctx)
+{
+	cgit_print_log(ctx->qry.sha1, ctx->qry.ofs, ctx->cfg.max_commit_count,
+		       ctx->qry.grep, ctx->qry.search, ctx->qry.path, 1);
+}
+
+static void patch_fn(struct cgit_context *ctx)
+{
+	cgit_print_patch(ctx->qry.sha1);
+}
+
+static void refs_fn(struct cgit_context *ctx)
+{
+	cgit_print_refs();
+}
+
+static void snapshot_fn(struct cgit_context *ctx)
+{
+	cgit_print_snapshot(ctx->qry.head, ctx->qry.sha1,
+			    cgit_repobasename(ctx->repo->url), ctx->qry.path,
+			    ctx->repo->snapshots);
+}
+
+static void summary_fn(struct cgit_context *ctx)
+{
+	cgit_print_summary();
+}
+
+static void tag_fn(struct cgit_context *ctx)
+{
+	cgit_print_tag(ctx->qry.sha1);
+}
+
+static void tree_fn(struct cgit_context *ctx)
+{
+	cgit_print_tree(ctx->qry.sha1, ctx->qry.path);
+}
+
+#define def_cmd(name, want_repo, want_layout) \
+	{#name, name##_fn, want_repo, want_layout}
+
+struct cgit_cmd *cgit_get_cmd(struct cgit_context *ctx)
+{
+	static struct cgit_cmd cmds[] = {
+		def_cmd(blob, 1, 0),
+		def_cmd(commit, 1, 1),
+		def_cmd(diff, 1, 1),
+		def_cmd(log, 1, 1),
+		def_cmd(patch, 1, 0),
+		def_cmd(refs, 1, 1),
+		def_cmd(repolist, 0, 0),
+		def_cmd(snapshot, 1, 0),
+		def_cmd(summary, 1, 1),
+		def_cmd(tag, 1, 1),
+		def_cmd(tree, 1, 1),
+	};
+	int i;
+
+	if (ctx->qry.page == NULL) {
+		if (ctx->repo)
+			ctx->qry.page = "summary";
+		else
+			ctx->qry.page = "repolist";
+	}
+
+	for(i = 0; i < sizeof(cmds)/sizeof(*cmds); i++)
+		if (!strcmp(ctx->qry.page, cmds[i].name))
+			return &cmds[i];
+	return NULL;
+}
diff --git a/cmd.h b/cmd.h
new file mode 100644
index 0000000..ec9e691
--- a/dev/null
+++ b/cmd.h
@@ -0,0 +1,15 @@
+#ifndef CMD_H
+#define CMD_H
+
+typedef void (*cgit_cmd_fn)(struct cgit_context *ctx);
+
+struct cgit_cmd {
+	const char *name;
+	cgit_cmd_fn fn;
+	unsigned int want_repo:1,
+		want_layout:1;
+};
+
+extern struct cgit_cmd *cgit_get_cmd(struct cgit_context *ctx);
+
+#endif /* CMD_H */
diff --git a/parsing.c b/parsing.c
index 027f06b..8dce488 100644
--- a/parsing.c
+++ b/parsing.c
@@ -161,26 +161,26 @@ void cgit_parse_url(const char *url)
 			cmd[0] = '/';
 			cmd = strchr(cmd + 1, '/');
 			continue;
 		}
 
 		ctx.qry.repo = ctx.repo->url;
 		p = strchr(cmd + 1, '/');
 		if (p) {
 			p[0] = '\0';
 			if (p[1])
 				ctx.qry.path = trim_end(p + 1, '/');
 		}
-		cgit_cmd = cgit_get_cmd_index(cmd + 1);
-		ctx.qry.page = xstrdup(cmd + 1);
+		if (cmd[1])
+			ctx.qry.page = xstrdup(cmd + 1);
 		return;
 	}
 }
 
 char *substr(const char *head, const char *tail)
 {
 	char *buf;
 
 	buf = xmalloc(tail - head + 1);
 	strncpy(buf, head, tail - head);
 	buf[tail - head] = '\0';
 	return buf;
diff --git a/shared.c b/shared.c
index 539d533..67eb67b 100644
--- a/shared.c
+++ b/shared.c
@@ -31,36 +31,24 @@ void cgit_prepare_context(struct cgit_context *ctx)
 	ctx->cfg.max_msg_len = 60;
 	ctx->cfg.max_repodesc_len = 60;
 	ctx->cfg.module_link = "./?repo=%s&page=commit&id=%s";
 	ctx->cfg.renamelimit = -1;
 	ctx->cfg.robots = "index, nofollow";
 	ctx->cfg.root_title = "Git repository browser";
 	ctx->cfg.script_name = CGIT_SCRIPT_NAME;
 	ctx->page.mimetype = "text/html";
 	ctx->page.charset = PAGE_ENCODING;
 	ctx->page.filename = NULL;
 }
 
-int cgit_get_cmd_index(const char *cmd)
-{
-	static char *cmds[] = {"log", "commit", "diff", "tree", "blob",
-			       "snapshot", "tag", "refs", "patch", NULL};
-	int i;
-
-	for(i = 0; cmds[i]; i++)
-		if (!strcmp(cmd, cmds[i]))
-			return i + 1;
-	return 0;
-}
-
 int chk_zero(int result, char *msg)
 {
 	if (result != 0)
 		die("%s: %s", msg, strerror(errno));
 	return result;
 }
 
 int chk_positive(int result, char *msg)
 {
 	if (result <= 0)
 		die("%s: %s", msg, strerror(errno));
 	return result;
@@ -207,25 +195,24 @@ void cgit_global_config_cb(const char *name, const char *value)
 			ctx.repo->readme = xstrdup(fmt("%s/%s", ctx.repo->path, value));
 	} else if (!strcmp(name, "include"))
 		cgit_read_config(value, cgit_global_config_cb);
 }
 
 void cgit_querystring_cb(const char *name, const char *value)
 {
 	if (!strcmp(name,"r")) {
 		ctx.qry.repo = xstrdup(value);
 		ctx.repo = cgit_get_repoinfo(value);
 	} else if (!strcmp(name, "p")) {
 		ctx.qry.page = xstrdup(value);
-		cgit_cmd = cgit_get_cmd_index(value);
 	} else if (!strcmp(name, "url")) {
 		cgit_parse_url(value);
 	} else if (!strcmp(name, "qt")) {
 		ctx.qry.grep = xstrdup(value);
 	} else if (!strcmp(name, "q")) {
 		ctx.qry.search = xstrdup(value);
 	} else if (!strcmp(name, "h")) {
 		ctx.qry.head = xstrdup(value);
 		ctx.qry.has_symref = 1;
 	} else if (!strcmp(name, "id")) {
 		ctx.qry.sha1 = xstrdup(value);
 		ctx.qry.has_sha1 = 1;