Re: [RFC] Git config file reader in Perl (WIP)

[Eric Wong <normalperson@yhbt.net>]

Jakub Narebski <jnareb@gmail.com> wrote:
> Eric Wong wrote:
> > Jakub Narebski <jnareb@gmail.com> wrote:
> >> Eric Wong wrote:
> >>> Jakub Narebski <jnareb@gmail.com> wrote:
> >>>> To make gitweb faster I thought about adding to it, or to Git.pm,
> >>>> simple nonvalidation config file reader. Nonvalidating means that
> >>>> it would accept some input which git-repo-config considers invalid.
> >>> 
> >>> How about something like git-for-each-ref that dumps the entire output
> >>> of a config file into an eval()-able string?  That way we don't have to
> >>> deal with corner-cases and subtle differences between C and Perl
> >>> implementations.
> >> 
> >> The idea is (at least for gitweb) to avoid cost of fork. And I think
> >> if the format gets documented properly, there should be no differences
> >> in config file parsing.
> > 
> > If the Perl output is redirected to a file (say .git/config.perl) and
> > only regenerated when .git/config changes, `do(".git/config.perl")' will
> > likely be faster since all the parsing will be done by Perl itself.
> 
> Would you write "git repo-config --perl", then? ;-)

The below patch should be a start (only tested on my fairly standard
.git/config).  A --python option should be easy, too :)

> Besides, I'd rather avoid the need for /tmp/gitweb, and I think usually
> gitweb do not have (and should not have) write access to repository.

Good point.  Having to maintain a .git/config.perl in the repository
would be a pain from an administrative standpoint; but on the other hand
.git/config is not often regenerated.

I don't think giving gitweb write access to a repo is a good idea;
either.  Perhaps it would be updated via hook like the HTTP stuff.
IMHO, there is nothing wrong with gitweb writing to /tmp; however.

diff --git a/builtin-repo-config.c b/builtin-repo-config.c
index 9063311..a9ef358 100644
--- a/builtin-repo-config.c
+++ b/builtin-repo-config.c
@@ -1,5 +1,6 @@
 #include "builtin.h"
 #include "cache.h"
+#include "quote.h"
 
 static const char git_config_set_usage[] =
 "git-repo-config [ --global ] [ --bool | --int ] [--get | --get-all | --get-regexp | --replace-all | --add | --unset | --unset-all] name [value [value_regex]] | --rename-section old_name new_name | --list";
@@ -13,6 +14,7 @@ static int do_all;
 static int do_not_match;
 static int seen;
 static enum { T_RAW, T_INT, T_BOOL } type = T_RAW;
+static char *last_key;
 
 static int show_all_config(const char *key_, const char *value_)
 {
@@ -23,6 +25,30 @@ static int show_all_config(const char *key_, const char *value_)
 	return 0;
 }
 
+static int show_perl_config(const char *key_, const char *value_)
+{
+	if (last_key) {
+		if (strcmp(last_key, key_)) {
+			free(last_key);
+			last_key = xstrdup(key_);
+			fputs("\t],\n\t", stdout);
+			perl_quote_print(stdout, key_);
+			fputs(" => [\n", stdout);
+		}
+	} else {
+		last_key = xstrdup(key_);
+		fputc('\t', stdout);
+		perl_quote_print(stdout, key_);
+		fputs(" => [\n", stdout);
+	}
+	if (value_) {
+		fputs("\t\t", stdout);
+		perl_quote_print(stdout, value_);
+		fputs(",\n", stdout);
+	}
+	return 0;
+}
+
 static int show_config(const char* key_, const char* value_)
 {
 	char value[256];
@@ -138,6 +164,17 @@ int cmd_repo_config(int argc, const char **argv, const char *prefix)
 			type = T_BOOL;
 		else if (!strcmp(argv[1], "--list") || !strcmp(argv[1], "-l"))
 			return git_config(show_all_config);
+		else if (!strcmp(argv[1], "--perl")) {
+			int rv;
+			puts("\%git_config = (");
+			rv = git_config(show_perl_config);
+			if (last_key) {
+				puts("\t]\n);\n");
+				free(last_key);
+				last_key = NULL;
+			}
+			return rv;
+		}
 		else if (!strcmp(argv[1], "--global")) {
 			char *home = getenv("HOME");
 			if (home) {

-- 
Eric Wong