1/* ui-snapshot.c: generate snapshot of a commit
  2 *
  3 * Copyright (C) 2006 Lars Hjemli
  4 *
  5 * Licensed under GNU General Public License v2
  6 *   (see COPYING for full license text)
  7 */
  8
  9#include "cgit.h"
 10#include "html.h"
 11#include "ui-shared.h"
 12
 13static int write_compressed_tar_archive(struct archiver_args *args,const char *filter)
 14{
 15	int rw[2];
 16	pid_t gzpid;
 17	int stdout2;
 18	int status;
 19	int rv;
 20
 21	stdout2 = chk_non_negative(dup(STDIN_FILENO), "Preserving STDOUT before compressing");
 22	chk_zero(pipe(rw), "Opening pipe from compressor subprocess");
 23	gzpid = chk_non_negative(fork(), "Forking compressor subprocess");
 24	if(gzpid==0) {
 25		/* child */
 26		chk_zero(close(rw[1]), "Closing write end of pipe in child");
 27		chk_zero(close(STDIN_FILENO), "Closing STDIN");
 28		chk_non_negative(dup2(rw[0],STDIN_FILENO), "Redirecting compressor input to stdin");
 29		execlp(filter,filter,NULL);
 30		_exit(-1);
 31	}
 32	/* parent */
 33	chk_zero(close(rw[0]), "Closing read end of pipe");
 34	chk_non_negative(dup2(rw[1],STDOUT_FILENO), "Redirecting output to compressor");
 35
 36	rv = write_tar_archive(args);
 37
 38	chk_zero(close(STDOUT_FILENO), "Closing STDOUT redirected to compressor");
 39	chk_non_negative(dup2(stdout2,STDOUT_FILENO), "Restoring uncompressed STDOUT");
 40	chk_zero(close(stdout2), "Closing uncompressed STDOUT");
 41	chk_zero(close(rw[1]), "Closing write end of pipe in parent");
 42	chk_positive(waitpid(gzpid,&status,0), "Waiting on compressor process");
 43	if(! ( WIFEXITED(status) && WEXITSTATUS(status)==0 ) )
 44		cgit_print_error("Failed to compress archive");
 45
 46	return rv;
 47}
 48
 49static int write_tar_gzip_archive(struct archiver_args *args)
 50{
 51	return write_compressed_tar_archive(args,"gzip");
 52}
 53
 54static int write_tar_bzip2_archive(struct archiver_args *args)
 55{
 56	return write_compressed_tar_archive(args,"bzip2");
 57}
 58
 59const struct cgit_snapshot_format cgit_snapshot_formats[] = {
 60	{ ".zip", "application/x-zip", write_zip_archive, 0x1 },
 61	{ ".tar.gz", "application/x-tar", write_tar_gzip_archive, 0x2 },
 62	{ ".tar.bz2", "application/x-tar", write_tar_bzip2_archive, 0x4 },
 63	{ ".tar", "application/x-tar", write_tar_archive, 0x8 },
 64	{}
 65};
 66
 67static const struct cgit_snapshot_format *get_format(const char *filename)
 68{
 69	const struct cgit_snapshot_format *fmt;
 70	int fl, sl;
 71
 72	fl = strlen(filename);
 73	for(fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
 74		sl = strlen(fmt->suffix);
 75		if (sl >= fl)
 76			continue;
 77		if (!strcmp(fmt->suffix, filename + fl - sl))
 78			return fmt;
 79	}
 80	return NULL;
 81}
 82
 83static int make_snapshot(const struct cgit_snapshot_format *format,
 84			 const char *hex, const char *prefix,
 85			 const char *filename)
 86{
 87	struct archiver_args args;
 88	struct commit *commit;
 89	unsigned char sha1[20];
 90
 91	if(get_sha1(hex, sha1)) {
 92		cgit_print_error(fmt("Bad object id: %s", hex));
 93		return 1;
 94	}
 95	commit = lookup_commit_reference(sha1);
 96	if(!commit) {
 97		cgit_print_error(fmt("Not a commit reference: %s", hex));
 98		return 1;
 99	}
100	memset(&args, 0, sizeof(args));
101	if (prefix) {
102		args.base = fmt("%s/", prefix);
103		args.baselen = strlen(prefix) + 1;
104	} else {
105		args.base = "";
106		args.baselen = 0;
107	}
108	args.tree = commit->tree;
109	args.time = commit->date;
110	ctx.page.mimetype = xstrdup(format->mimetype);
111	ctx.page.filename = xstrdup(filename);
112	cgit_print_http_headers(&ctx);
113	format->write_func(&args);
114	return 0;
115}
116
117char *dwim_filename = NULL;
118const char *dwim_refname = NULL;
119
120static int ref_cb(const char *refname, const unsigned char *sha1, int flags,
121		  void *cb_data)
122{
123	const char *r = refname;
124	while (r && *r) {
125		fprintf(stderr, "  cmp %s with %s:", dwim_filename, r);
126		if (!strcmp(dwim_filename, r)) {
127			fprintf(stderr, "MATCH!\n");
128			dwim_refname = refname;
129			return 1;
130		}
131		fprintf(stderr, "no match\n");
132		if (isdigit(*r))
133			break;
134		r++;
135	}
136	return 0;
137}
138
139/* Try to guess the requested revision by combining repo name and tag name
140 * and comparing this to the requested snapshot name. E.g. the requested
141 * snapshot is "cgit-0.7.2.tar.gz" while repo name is "cgit" and tag name
142 * is "v0.7.2". First, the reponame is stripped off, leaving "-0.7.2.tar.gz".
143 * Next, any '-' and '_' characters are stripped, leaving "0.7.2.tar.gz".
144 * Finally, the requested format suffix is removed and we end up with "0.7.2".
145 * Then we test each tag against this dwimmed filename, and for each tag
146 * we even try to remove any leading characters which are non-digits. I.e.
147 * we first compare with "v0.7.2", then with "0.7.2" and we've got a match.
148 */
149static const char *get_ref_from_filename(const char *url, const char *filename,
150					 const struct cgit_snapshot_format *fmt)
151{
152	const char *reponame = cgit_repobasename(url);
153	fprintf(stderr, "reponame=%s, filename=%s\n", reponame, filename);
154	if (prefixcmp(filename, reponame))
155		return NULL;
156	filename += strlen(reponame);
157	while (filename && (*filename == '-' || *filename == '_'))
158		filename++;
159	dwim_filename = xstrdup(filename);
160	dwim_filename[strlen(filename) - strlen(fmt->suffix)] = '\0';
161	for_each_tag_ref(ref_cb, NULL);
162	return dwim_refname;
163}
164
165void cgit_print_snapshot(const char *head, const char *hex, const char *prefix,
166			 const char *filename, int snapshots, int dwim)
167{
168	const struct cgit_snapshot_format* f;
169
170	f = get_format(filename);
171	if (!f) {
172		ctx.page.mimetype = "text/html";
173		cgit_print_http_headers(&ctx);
174		cgit_print_docstart(&ctx);
175		cgit_print_pageheader(&ctx);
176		cgit_print_error(fmt("Unsupported snapshot format: %s", filename));
177		cgit_print_docend();
178		return;
179	}
180
181	if (!hex && dwim)
182		hex = get_ref_from_filename(ctx.repo->url, filename, f);
183
184	if (!hex)
185		hex = head;
186
187	make_snapshot(f, hex, prefix, filename);
188}