reference.c

Branch :
Show log
Commit
Author : Stefan Sperling
Date : 2019-02-02 15:00:28
Hash : 199a4027
Message : make 'got log' show packed refs and HEAD ref (pther refs not shown yet)
lib/reference.c
/*
 * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/queue.h>

#include <sha1.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <util.h>
#include <zlib.h>
#include <time.h>

#include "got_error.h"
#include "got_object.h"
#include "got_repository.h"
#include "got_reference.h"

#include "got_lib_sha1.h"
#include "got_lib_path.h"
#include "got_lib_delta.h"
#include "got_lib_inflate.h"
#include "got_lib_object.h"

#ifndef nitems
#define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
#endif

#define GOT_REF_HEADS	"heads"
#define GOT_REF_TAGS	"tags"
#define GOT_REF_REMOTES	"remotes"

/* A symbolic reference. */
struct got_symref {
	char *name;
	char *ref;
};

/* A non-symbolic reference (there is no better designation). */
struct got_ref {
	char *name;
	u_int8_t sha1[SHA1_DIGEST_LENGTH];
};

/* A reference which points to an arbitrary object. */
struct got_reference {
	unsigned int flags;
#define GOT_REF_IS_SYMBOLIC	0x01

	union {
		struct got_ref ref;
		struct got_symref symref;
	} ref;
};

static const struct got_error *
parse_symref(struct got_reference **ref, const char *name, const char *line)
{
	struct got_symref *symref;
	char *symref_name;
	char *symref_ref;

	if (line[0] == '\0')
		return got_error(GOT_ERR_NOT_REF);

	symref_name = strdup(name);
	if (symref_name == NULL)
		return got_error_from_errno();
	symref_ref = strdup(line);
	if (symref_ref == NULL) {
		const struct got_error *err = got_error_from_errno();
		free(symref_name);
		return err;
	}

	*ref = calloc(1, sizeof(**ref));
	if (*ref == NULL)
		return got_error_from_errno();
	(*ref)->flags |= GOT_REF_IS_SYMBOLIC;
	symref = &((*ref)->ref.symref);
	symref->name = symref_name;
	symref->ref = symref_ref;
	return NULL;
}

static const struct got_error *
parse_ref_line(struct got_reference **ref, const char *name, const char *line)
{
	uint8_t digest[SHA1_DIGEST_LENGTH];
	char *ref_name;

	if (strncmp(line, "ref: ", 5) == 0) {
		line += 5;
		return parse_symref(ref, name, line);
	}

	ref_name = strdup(name);
	if (ref_name == NULL)
		return got_error_from_errno();

	if (!got_parse_sha1_digest(digest, line))
		return got_error(GOT_ERR_NOT_REF);

	*ref = calloc(1, sizeof(**ref));
	if (*ref == NULL)
		return got_error_from_errno();
	(*ref)->ref.ref.name = ref_name;
	memcpy(&(*ref)->ref.ref.sha1, digest, SHA1_DIGEST_LENGTH);
	return NULL;
}

static const struct got_error *
parse_ref_file(struct got_reference **ref, const char *name,
    const char *abspath)
{
	const struct got_error *err = NULL;
	FILE *f = fopen(abspath, "rb");
	char *line;
	size_t len;
	const char delim[3] = {'\0', '\0', '\0'};

	if (f == NULL)
		return got_error(GOT_ERR_NOT_REF);

	line = fparseln(f, &len, NULL, delim, 0);
	if (line == NULL) {
		err = got_error(GOT_ERR_NOT_REF);
		goto done;
	}

	err = parse_ref_line(ref, name, line);
done:
	free(line);
	fclose(f);
	return err;
}

static int
is_well_known_ref(const char *refname)
{
	return (strcmp(refname, GOT_REF_HEAD) == 0 ||
	    strcmp(refname, GOT_REF_ORIG_HEAD) == 0 ||
	    strcmp(refname, GOT_REF_MERGE_HEAD) == 0 ||
	    strcmp(refname, GOT_REF_FETCH_HEAD) == 0);
}

static char *
get_refs_dir_path(struct got_repository *repo, const char *refname)
{
	if (is_well_known_ref(refname) || strncmp(refname, "refs/", 5) == 0)
		return strdup(got_repo_get_path_git_dir(repo));

	return got_repo_get_path_refs(repo);
}

static const struct got_error *
parse_packed_ref_line(struct got_reference **ref, const char *abs_refname,
    const char *line)
{
	uint8_t digest[SHA1_DIGEST_LENGTH];
	char *name;

	*ref = NULL;

	if (line[0] == '#' || line[0] == '^')
		return NULL;

	if (!got_parse_sha1_digest(digest, line))
		return got_error(GOT_ERR_NOT_REF);

	if (abs_refname) {
		if (strcmp(line + SHA1_DIGEST_STRING_LENGTH, abs_refname) != 0)
			return NULL;

		name = strdup(abs_refname);
		if (name == NULL)
			return got_error_from_errno();
	} else
		name = strdup(line + SHA1_DIGEST_STRING_LENGTH);

	*ref = calloc(1, sizeof(**ref));
	if (*ref == NULL)
		return got_error_from_errno();
	(*ref)->ref.ref.name = name;;
	memcpy(&(*ref)->ref.ref.sha1, digest, SHA1_DIGEST_LENGTH);
	return NULL;
}

static const struct got_error *
open_packed_ref(struct got_reference **ref, FILE *f, const char **subdirs,
    int nsubdirs, const char *refname)
{
	const struct got_error *err = NULL;
	char *abs_refname;
	char *line;
	size_t len;
	const char delim[3] = {'\0', '\0', '\0'};
	int i, ref_is_absolute = (strncmp(refname, "refs/", 5) == 0);

	if (ref_is_absolute)
		abs_refname = (char *)refname;
	do {
		line = fparseln(f, &len, NULL, delim, 0);
		if (line == NULL) {
			err = got_error(GOT_ERR_NOT_REF);
			break;
		}
		for (i = 0; i < nsubdirs; i++) {
			if (!ref_is_absolute &&
			    asprintf(&abs_refname, "refs/%s/%s", subdirs[i],
			    refname) == -1)
				return got_error_from_errno();
			err = parse_packed_ref_line(ref, abs_refname, line);
			if (!ref_is_absolute)
				free(abs_refname);
			if (err || *ref != NULL)
				break;
		}
		free(line);
		if (err)
			break;
	} while (*ref == NULL);

	return err;
}

static const struct got_error *
open_ref(struct got_reference **ref, const char *path_refs, const char *subdir,
    const char *refname)
{
	const struct got_error *err = NULL;
	char *path_ref;
	char *normpath;

	if (asprintf(&path_ref, "%s/%s/%s", path_refs, subdir, refname) == -1)
		return got_error_from_errno();

	normpath = got_path_normalize(path_ref);
	if (normpath == NULL) {
		err = got_error(GOT_ERR_NOT_REF);
		goto done;
	}

	err = parse_ref_file(ref, refname, normpath);
done:
	free(path_ref);
	free(normpath);
	return err;
}

const struct got_error *
got_ref_open(struct got_reference **ref, struct got_repository *repo,
   const char *refname)
{
	const struct got_error *err = NULL;
	char *path_refs = NULL;
	const char *subdirs[] = {
	    GOT_REF_HEADS, GOT_REF_TAGS, GOT_REF_REMOTES
	};
	int i, well_known = is_well_known_ref(refname);

	if (!well_known) {
		char *packed_refs_path;
		FILE *f;

		packed_refs_path = got_repo_get_path_packed_refs(repo);
		if (packed_refs_path == NULL)
			return got_error_from_errno();

		f = fopen(packed_refs_path, "rb");
		free(packed_refs_path);
		if (f != NULL) {
			err = open_packed_ref(ref, f, subdirs, nitems(subdirs),
			    refname);
			fclose(f);
			if (err == NULL)
				goto done;
		}
	}

	path_refs = get_refs_dir_path(repo, refname);
	if (path_refs == NULL) {
		err = got_error_from_errno();
		goto done;
	}

	if (!well_known) {
		for (i = 0; i < nitems(subdirs); i++) {
			err = open_ref(ref, path_refs, subdirs[i], refname);
			if (err == NULL)
				goto done;
		}
	}

	err = open_ref(ref, path_refs, "", refname);
done:
	free(path_refs);
	return err;
}

void
got_ref_close(struct got_reference *ref)
{
	if (ref->flags & GOT_REF_IS_SYMBOLIC)
		free(ref->ref.symref.name);
	else
		free(ref->ref.ref.name);
	free(ref);
}

struct got_reference *
got_ref_dup(struct got_reference *ref)
{
	struct got_reference *ret;

	ret = calloc(1, sizeof(*ret));
	if (ret == NULL)
		return NULL;

	ret->flags = ref->flags;
	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
		ret->ref.symref.name = strdup(ref->ref.symref.name);
		if (ret->ref.symref.name == NULL) {
			free(ret);
			return NULL;
		}
		ret->ref.symref.ref = strdup(ref->ref.symref.ref);
		if (ret->ref.symref.ref == NULL) {
			free(ret->ref.symref.name);
			free(ret);
			return NULL;
		}
	} else {
		ref->ref.ref.name = strdup(ref->ref.ref.name);
		if (ref->ref.ref.name == NULL) {
			free(ret);
			return NULL;
		}
		memcpy(ret->ref.ref.sha1, ref->ref.ref.sha1,
		    SHA1_DIGEST_LENGTH);
	}

	return ret;
}

static const struct got_error *
resolve_symbolic_ref(struct got_reference **resolved,
    struct got_repository *repo, struct got_reference *ref)
{
	struct got_reference *nextref;
	const struct got_error *err;

	err = got_ref_open(&nextref, repo, ref->ref.symref.ref);
	if (err)
		return err;

	if (nextref->flags & GOT_REF_IS_SYMBOLIC)
		err = resolve_symbolic_ref(resolved, repo, nextref);
	else
		*resolved = got_ref_dup(nextref);

	got_ref_close(nextref);
	return err;
}

const struct got_error *
got_ref_resolve(struct got_object_id **id, struct got_repository *repo,
    struct got_reference *ref)
{
	const struct got_error *err;

	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
		struct got_reference *resolved = NULL;
		err = resolve_symbolic_ref(&resolved, repo, ref);
		if (err == NULL)
			err = got_ref_resolve(id, repo, resolved);
		free(resolved);
		return err;
	}

	*id = calloc(1, sizeof(**id));
	if (*id == NULL)
		return got_error_from_errno();
	memcpy((*id)->sha1, ref->ref.ref.sha1, SHA1_DIGEST_LENGTH);
	return NULL;
}

char *
got_ref_to_str(struct got_reference *ref)
{
	char *str;

	if (ref->flags & GOT_REF_IS_SYMBOLIC)
		return strdup(ref->ref.symref.ref);

	str = malloc(SHA1_DIGEST_STRING_LENGTH);
	if (str == NULL)
		return NULL;

	if (got_sha1_digest_to_str(ref->ref.ref.sha1, str,
	    SHA1_DIGEST_STRING_LENGTH) == NULL) {
		free(str);
		return NULL;
	}

	return str;
}

const char *
got_ref_get_name(struct got_reference *ref)
{
	if (ref->flags & GOT_REF_IS_SYMBOLIC)
		return ref->ref.symref.name;

	return ref->ref.ref.name;
}

static const struct got_error *
append_ref(struct got_reflist_head *refs, struct got_reference *ref,
    struct got_repository *repo)
{
	const struct got_error *err;
	struct got_object_id *id;
	struct got_reflist_entry *entry;

	err = got_ref_resolve(&id, repo, ref);
	if (err)
		return err;
	entry = malloc(sizeof(*entry));
	if (entry == NULL)
		return got_error_from_errno();
	entry->ref = ref;
	entry->id = id;
	SIMPLEQ_INSERT_TAIL(refs, entry, entry);
	return NULL;
}

const struct got_error *
got_ref_list(struct got_reflist_head *refs, struct got_repository *repo)
{
	const struct got_error *err;
	char *packed_refs_path, *path_refs;
	FILE *f;
	struct got_reference *ref;

	packed_refs_path = got_repo_get_path_packed_refs(repo);
	if (packed_refs_path == NULL)
		return got_error_from_errno();

	f = fopen(packed_refs_path, "r");
	free(packed_refs_path);
	if (f) {
		char *line;
		size_t len;
		const char delim[3] = {'\0', '\0', '\0'};
		while (1) {
			line = fparseln(f, &len, NULL, delim, 0);
			if (line == NULL)
				break;
			err = parse_packed_ref_line(&ref, NULL, line);
			if (err)
				goto done;
			if (ref)
				append_ref(refs, ref, repo);
		}
	}

	/* HEAD ref should always exist. */
	path_refs = get_refs_dir_path(repo, GOT_REF_HEAD);
	if (path_refs == NULL) {
		err = got_error_from_errno();
		goto done;
	}
	err = open_ref(&ref, path_refs, "", GOT_REF_HEAD);
	free(path_refs);
	if (err)
		goto done;
	append_ref(refs, ref, repo);

done:
	if (f)
		fclose(f);
	return err;
}
thodg/got/lib/reference.c

Commit

thodg/got /lib/reference.c
