eeshow/: option -H path_into_repo to list branched history of repository

eeshow/Makefile

@@ -13,7 +13,7 @@
 NAME = eeshow
 OBJS = main.o sch-parse.o sch-render.o lib-parse.o lib-render.o \
        gui.o gui-over.o gui-aoi.o \
-       file.o git-file.o \
+       file.o git-file.o git-hist.o \
        style.o fig.o record.o cro.o diff.o gfx.o dwg.o text.o misc.o
 
 CFLAGS = -g  -Wall -Wextra -Wno-unused-parameter -Wshadow \

eeshow/git-hist.c

@@ -0,0 +1,196 @@
+/*
+ * git-hist.c - Retrieve revision history from GIT repo
+ *
+ * Written 2016 by Werner Almesberger
+ * Copyright 2016 by Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <alloca.h>
+
+#include "util.h"
+#include "main.h"
+#include "git-hist.h"
+
+
+/*
+ * @@@ we assume to have a single head. That isn't necessarily true, since
+ * each open branch has its own head. Getting this right is for further study.
+ */
+
+
+static struct hist *new_commit(unsigned branch)
+{
+	struct hist *h;
+
+	h = alloc_type(struct hist);
+	h->commit = NULL;
+	h->branch = branch;
+	h->newer = NULL;
+	h->n_newer = 0;
+	h->older = NULL;
+	h->n_older = 0;
+	return h;
+}
+
+
+static void uplink(struct hist *down, struct hist *up)
+{
+	down->newer = realloc(down->newer,
+	    sizeof(struct hist *) * (down->n_newer + 1));
+	if (!down->newer) {
+		perror("realloc");
+		exit(1);
+	}
+	down->newer[down->n_newer++] = up;
+}
+
+
+static struct hist *find_commit(struct hist *h, const git_commit *commit)
+{
+	unsigned i;
+	struct hist *found;
+
+	/*
+	 * @@@ should probably use
+	 * git_oid_equal(git_object_id(a), git_object_id(b))
+	 */
+	if (h->commit == commit)
+		return h;
+	for (i = 0; i != h->n_older; i++) {
+		if (h->older[i]->newer[0] != h)
+			continue;
+		found = find_commit(h->older[i], commit);
+		if (found)
+			return found;
+	}
+	return NULL;
+}
+
+
+static void recurse(struct hist *h,
+    unsigned n_branches, struct hist **branches)
+{
+	unsigned n, i, j;
+	struct hist **b;
+	const git_error *e;
+
+	n = git_commit_parentcount(h->commit);
+	if (verbose > 2)
+		fprintf(stderr, "commit %p: %u + %u\n",
+		    h->commit, n_branches, n);
+
+	b = alloca(sizeof(struct hist) * (n_branches - 1 + n));
+	n_branches--;
+	memcpy(b, branches, sizeof(struct hist *) * n_branches);
+
+	h->older = alloc_size(sizeof(struct hist *) * n);
+	h->n_older = n;
+
+	for (i = 0; i != n; i++) {
+		git_commit *commit;
+		struct hist *found = NULL;
+
+		if (git_commit_parent(&commit, h->commit, i)) {
+			e = giterr_last();
+			fprintf(stderr, "git_commit_parent: %s\n", e->message);
+			exit(1);
+		}
+		for (j = 0; j != n_branches; j++) {
+			found = find_commit(b[j], commit);
+			if (found)
+				break;
+		}
+		if (found) {
+			uplink(found, h);
+			h->older[i] = found;
+		} else {
+			struct hist *new;
+
+			new = new_commit(n_branches);
+			new->commit = commit;
+			h->older[i] = new;
+			b[n_branches++] = new;
+			uplink(new, h);
+			recurse(new, n_branches, b);
+		}
+	}
+}
+
+
+struct hist *vcs_git_hist(const char *path)
+{
+	struct hist *head;
+	git_repository *repo;
+	git_oid oid;
+	const git_error *e;
+
+	head = new_commit(0);
+
+	git_libgit2_init(); /* @@@ */
+	if (git_repository_open_ext(&repo, path,
+	    GIT_REPOSITORY_OPEN_CROSS_FS, NULL)) {
+		e = giterr_last();
+		fprintf(stderr, "%s: %s\n", path, e->message);
+		exit(1);
+	}
+
+	if (git_reference_name_to_id(&oid, repo, "HEAD")) {
+		e = giterr_last();
+		fprintf(stderr, "%s: %s\n",
+		    git_repository_path(repo), e->message);
+		exit(1);
+	}
+
+	if (git_commit_lookup(&head->commit, repo, &oid)) {
+		e = giterr_last();
+		fprintf(stderr, "%s: %s\n",
+		    git_repository_path(repo), e->message);
+		exit(1);
+	}
+
+	recurse(head, 1, &head);
+	return head;
+}
+
+
+const char *vcs_git_summary(struct hist *h)
+{
+	const char *summary;
+	const git_error *e;
+
+	summary = git_commit_summary(h->commit);
+	if (summary)
+		return summary;
+
+	e = giterr_last();
+	fprintf(stderr, "git_commit_summary: %s\n", e->message);
+	exit(1);
+}
+
+
+void dump_hist(struct hist *h)
+{
+	git_buf buf = { 0 };
+	const git_error *e;
+	unsigned i;
+
+	if (git_object_short_id(&buf, (git_object *) h->commit)) {
+		e = giterr_last();
+		fprintf(stderr, "git_object_short_id: %s\n", e->message);
+		exit(1);
+	}
+	printf("%*s%s  %s\n", 2 * h->branch, "", buf.ptr, vcs_git_summary(h));
+	git_buf_free(&buf);
+
+	for (i = 0; i != h->n_older; i++)
+		if (h->older[i]->newer[h->older[i]->n_newer - 1] == h)
+			dump_hist(h->older[i]);
+}

eeshow/git-hist.h

@@ -0,0 +1,36 @@
+/*
+ * git-hist.h - Retrieve revision history from GIT repo
+ *
+ * Written 2016 by Werner Almesberger
+ * Copyright 2016 by Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef GIT_HIST_H
+#define	GIT_HIST_H
+
+#include <git2.h>
+
+
+struct hist {
+	struct git_commit *commit;
+
+	unsigned branch;	/* branch index */
+
+	struct hist **newer;
+	unsigned n_newer;
+
+	struct hist **older;
+	unsigned n_older;
+};
+
+
+struct hist *vcs_git_hist(const char *path);
+const char *vcs_git_summary(struct hist *hist);
+void dump_hist(struct hist *h);
+
+#endif /* !GIT_HIST_H */

eeshow/main.c

@@ -27,6 +27,7 @@
 #include "file.h"
 #include "lib.h"
 #include "sch.h"
+#include "git-hist.h"
 #include "gui.h"
 #include "main.h"
 
@@ -48,11 +49,13 @@ void usage(const char *name)
 "usage: %s [-r] [-v ...] [[rev:]file.lib ...] [rev:]file.sch\n"
 "       %*s[-- driver_spec]\n"
 "       %s [-v ...] -C [rev:]file\n"
+"       %s [-v ...] -H path_into_repo\n"
 "\n"
 "  rev  git revision\n"
 "  -r   recurse into sub-sheets\n"
 "  -v   increase verbosity of diagnostic output\n"
 "  -C   'cat' the file to standard output\n"
+"  -H   show history of repository on standard output\n"
 "\n"
 "FIG driver spec:\n"
 "  fig [-t template.fig] [var=value ...]\n"
@@ -75,7 +78,7 @@ void usage(const char *name)
 "  diff [-o output.pdf] [-s scale] [file.lib ...] file.sch\n"
 "\n"
 "  see PNG\n"
-    , name, (int) strlen(name) + 1, "", name);
+    , name, (int) strlen(name) + 1, "", name, name);
 	exit(1);
 }
 
@@ -87,6 +90,7 @@ int main(int argc, char **argv)
 	struct file sch_file;
 	bool recurse = 0;
 	const char *cat = NULL;
+	const char *history = NULL;
 	char c;
 	int arg, dashdash;
 	bool have_dashdash = 0;
@@ -102,7 +106,7 @@ int main(int argc, char **argv)
 			break;
 		}
 
-	while ((c = getopt(dashdash, argv, "rvC:")) != EOF)
+	while ((c = getopt(dashdash, argv, "rvC:H:")) != EOF)
 		switch (c) {
 		case 'r':
 			recurse = 1;
@@ -113,6 +117,9 @@ int main(int argc, char **argv)
 		case 'C':
 			cat = optarg;
 			break;
+		case 'H':
+			history = optarg;
+			break;
 		default:
 			usage(*argv);
 		}
@@ -128,6 +135,14 @@ int main(int argc, char **argv)
 		return 0;
 	}
 
+	if (history) {
+		struct hist *h;
+
+		h = vcs_git_hist(history);
+		dump_hist(h);
+		return 0;
+	}
+
 	if (dashdash - optind < 1)
 		usage(*argv);