[RFCv2 PATCH 5/7] ui-blame: pull blame info from libgit

[john at keeping.me.uk (John Keeping)]

On Fri, Sep 22, 2017 at 10:38:46PM -0500, Jeff Smith wrote:
> Use the blame interface added in libgit to output the blame information
> of a file in the repository.
> 
> Signed-off-by: Jeff Smith <whydoubt at gmail.com>
> ---
> diff --git a/ui-blame.c b/ui-blame.c
> index 901ca89..cc4457a 100644
> --- a/ui-blame.c
> +++ b/ui-blame.c
> @@ -10,6 +10,183 @@
>  #include "ui-blame.h"
>  #include "html.h"
>  #include "ui-shared.h"
> +#include "argv-array.h"
> +#include "blame.h"
> +
> +
> +/*
> + * Information on commits, used for output.
> + */
> +struct commit_info {
> +	struct strbuf author;
> +	struct strbuf author_mail;
> +	struct ident_split author_ident;
> +
> +	/* filled only when asked for details */
> +	struct strbuf committer;
> +	struct strbuf committer_mail;
> +	struct ident_split committer_ident;
> +
> +	struct strbuf summary;
> +};

I think I commented on this last time, but I still don't understand why
this adds a new commit_info structure rather than reusing our existing
commitinfo and cgit_parse_commit(), especially since...

> +static void get_commit_info(struct commit *commit,
> +			    struct commit_info *ret,
> +			    int detailed)
> +{
> +	int len;
> +	const char *subject, *encoding;
> +	const char *message;
> +
> +	commit_info_init(ret);
> +
> +	encoding = get_log_output_encoding();

... this is wrong as our output encoding has nothing to do with the
environment but is specified by PAGE_ENCODING.

> +	message = logmsg_reencode(commit, NULL, encoding);
> +	get_ac_line(message, "\nauthor ",
> +		    &ret->author, &ret->author_mail,
> +		    &ret->author_ident);
> +
> +	if (!detailed) {
> +		unuse_commit_buffer(commit, message);
> +		return;
> +	}
> +
> +	get_ac_line(message, "\ncommitter ",
> +		    &ret->committer, &ret->committer_mail,
> +		    &ret->committer_ident);
> +
> +	len = find_commit_subject(message, &subject);
> +	if (len)
> +		strbuf_add(&ret->summary, subject, len);
> +	else
> +		strbuf_addf(&ret->summary, "(%s)", oid_to_hex(&commit->object.oid));
> +
> +	unuse_commit_buffer(commit, message);
> +}
> +
> +static char *emit_one_suspect_detail(struct blame_origin *suspect, const char *hex)
> +{
> +	struct commit_info ci;
> +	struct strbuf detail = STRBUF_INIT;
> +
> +	get_commit_info(suspect->commit, &ci, 1);
> +
> +	strbuf_addf(&detail, "author  %s", ci.author.buf);
> +	if (!ctx.cfg.noplainemail)
> +		strbuf_addf(&detail, " %s", ci.author_mail.buf);
> +	strbuf_addf(&detail, "  %s\n",
> +		    show_ident_date(&ci.author_ident,
> +				    cgit_date_mode(DATE_ISO8601)));
> +
> +	strbuf_addf(&detail, "committer  %s", ci.committer.buf);
> +	if (!ctx.cfg.noplainemail)
> +		strbuf_addf(&detail, " %s", ci.committer_mail.buf);
> +	strbuf_addf(&detail, "  %s\n\n",
> +		    show_ident_date(&ci.committer_ident,
> +				    cgit_date_mode(DATE_ISO8601)));
> +
> +	strbuf_addbuf(&detail, &ci.summary);
> +
> +	commit_info_destroy(&ci);
> +	return strbuf_detach(&detail, NULL);
> +}
> +
> +static void emit_blame_entry(struct blame_scoreboard *sb, struct blame_entry *ent)
> +{
> +	struct blame_origin *suspect = ent->suspect;
> +	char hex[GIT_SHA1_HEXSZ + 1];
> +	char *detail, *abbrev;
> +	unsigned long lineno;
> +	const char *numberfmt = "<a id='n%1$d' href='#n%1$d'>%1$d</a>\n";
> +	const char *cp, *cpend;
> +
> +	oid_to_hex_r(hex, &suspect->commit->object.oid);
> +	detail = emit_one_suspect_detail(suspect, hex);
> +	abbrev = xstrdup(find_unique_abbrev(suspect->commit->object.oid.hash,
> +					    DEFAULT_ABBREV));

nit: I don't think there's any need to strdup for abbrev, we use the
result immediately so the static buffer won't get overwritten.

> +	html("<tr><td class='lines'><pre>");
> +	cgit_commit_link(abbrev, detail, NULL, ctx.qry.head, hex, suspect->path);
> +	html("</pre></td>\n");
> +
> +	free(detail);
> +	free(abbrev);
> +
> +	if (ctx.cfg.enable_tree_linenumbers) {
> +		html("<td class='linenumbers'><pre>");
> +		lineno = ent->lno;
> +		while (lineno < ent->lno + ent->num_lines)
> +			htmlf(numberfmt, ++lineno);
> +		html("</pre></td>\n");
> +	}
> +
> +	cp = blame_nth_line(sb, ent->lno);
> +	cpend = blame_nth_line(sb, ent->lno + ent->num_lines);
> +
> +	html("<td class='lines'><pre><code>");
> +	html_ntxt(cpend - cp, cp);
> +	html("</code></pre></td></tr>\n");
> +}
>  
>  struct walk_tree_context {
>  	char *curr_rev;
> @@ -47,10 +224,16 @@ static void set_title_from_path(const char *path)
>  	strcat(new_title, ctx.page.title);
>  	ctx.page.title = new_title;
>  }
> +
>  static void print_object(const unsigned char *sha1, const char *path, const char *basename, const char *rev)
>  {
>  	enum object_type type;
>  	unsigned long size;
> +	struct argv_array rev_argv = ARGV_ARRAY_INIT;
> +	struct rev_info revs;
> +	struct blame_scoreboard sb;
> +	struct blame_origin *o;
> +	struct blame_entry *ent = NULL;
>  
>  	type = sha1_object_info(sha1, &size);
>  	if (type == OBJ_BAD) {
> @@ -59,7 +242,22 @@ static void print_object(const unsigned char *sha1, const char *path, const char
>  		return;
>  	}
>  
> -	/* Read in applicable data here */
> +	argv_array_push(&rev_argv, "blame");
> +	argv_array_push(&rev_argv, rev);
> +	init_revisions(&revs, NULL);
> +	DIFF_OPT_SET(&revs.diffopt, ALLOW_TEXTCONV);
> +	setup_revisions(rev_argv.argc, rev_argv.argv, &revs, NULL);
> +	init_scoreboard(&sb);
> +	sb.revs = &revs;
> +	setup_scoreboard(&sb, path, &o);
> +	o->suspects = blame_entry_prepend(NULL, 0, sb.num_lines, o);
> +	prio_queue_put(&sb.commits, o->commit);
> +	blame_origin_decref(o);
> +	sb.ent = NULL;
> +	sb.path = path;
> +	assign_blame(&sb, 0);
> +	blame_sort_final(&sb);
> +	blame_coalesce(&sb);
>  
>  	set_title_from_path(path);
>  
> @@ -76,7 +274,15 @@ static void print_object(const unsigned char *sha1, const char *path, const char
>  		return;
>  	}
>  
> -	/* Output data here */
> +	html("<table class='blame blob'>");
> +	for (ent = sb.ent; ent; ) {
> +		struct blame_entry *e = ent->next;
> +		emit_blame_entry(&sb, ent);
> +		free(ent);
> +		ent = e;
> +	}
> +	html("</table>\n");
> +	free((void *)sb.final_buf);
>  
>  	cgit_print_layout_end();
>  	return;