#include "../config.h"
#include "../refs.h"
#include "refs-internal.h"
-#include "ref-cache.h"
#include "packed-backend.h"
#include "../iterator.h"
#include "../lockfile.h"
-struct packed_ref_cache {
- struct ref_cache *cache;
+enum mmap_strategy {
+ /*
+ * Don't use mmap() at all for reading `packed-refs`.
+ */
+ MMAP_NONE,
/*
- * Count of references to the data structure in this instance,
- * including the pointer from files_ref_store::packed if any.
- * The data will not be freed as long as the reference count
- * is nonzero.
+ * Can use mmap() for reading `packed-refs`, but the file must
+ * not remain mmapped. This is the usual option on Windows,
+ * where you cannot rename a new version of a file onto a file
+ * that is currently mmapped.
*/
- unsigned int referrers;
+ MMAP_TEMPORARY,
- /* The metadata from when this packed-refs cache was read */
- struct stat_validity validity;
+ /*
+ * It is OK to leave the `packed-refs` file mmapped while
+ * arbitrary other code is running.
+ */
+ MMAP_OK
};
-/*
- * Increment the reference count of *packed_refs.
- */
-static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs)
-{
- packed_refs->referrers++;
-}
+#if defined(NO_MMAP)
+static enum mmap_strategy mmap_strategy = MMAP_NONE;
+#elif defined(MMAP_PREVENTS_DELETE)
+static enum mmap_strategy mmap_strategy = MMAP_TEMPORARY;
+#else
+static enum mmap_strategy mmap_strategy = MMAP_OK;
+#endif
+
+struct packed_ref_store;
/*
- * Decrease the reference count of *packed_refs. If it goes to zero,
- * free *packed_refs and return true; otherwise return false.
+ * A `snapshot` represents one snapshot of a `packed-refs` file.
+ *
+ * Normally, this will be a mmapped view of the contents of the
+ * `packed-refs` file at the time the snapshot was created. However,
+ * if the `packed-refs` file was not sorted, this might point at heap
+ * memory holding the contents of the `packed-refs` file with its
+ * records sorted by refname.
+ *
+ * `snapshot` instances are reference counted (via
+ * `acquire_snapshot()` and `release_snapshot()`). This is to prevent
+ * an instance from disappearing while an iterator is still iterating
+ * over it. Instances are garbage collected when their `referrers`
+ * count goes to zero.
+ *
+ * The most recent `snapshot`, if available, is referenced by the
+ * `packed_ref_store`. Its freshness is checked whenever
+ * `get_snapshot()` is called; if the existing snapshot is obsolete, a
+ * new snapshot is taken.
*/
-static int release_packed_ref_cache(struct packed_ref_cache *packed_refs)
-{
- if (!--packed_refs->referrers) {
- free_ref_cache(packed_refs->cache);
- stat_validity_clear(&packed_refs->validity);
- free(packed_refs);
- return 1;
- } else {
- return 0;
- }
-}
+struct snapshot {
+ /*
+ * A back-pointer to the packed_ref_store with which this
+ * snapshot is associated:
+ */
+ struct packed_ref_store *refs;
+
+ /* Is the `packed-refs` file currently mmapped? */
+ int mmapped;
+
+ /*
+ * The contents of the `packed-refs` file. If the file was
+ * already sorted, this points at the mmapped contents of the
+ * file. If not, this points at heap-allocated memory
+ * containing the contents, sorted. If there were no contents
+ * (e.g., because the file didn't exist), `buf` and `eof` are
+ * both NULL.
+ */
+ char *buf, *eof;
+
+ /* The size of the header line, if any; otherwise, 0: */
+ size_t header_len;
+
+ /*
+ * What is the peeled state of the `packed-refs` file that
+ * this snapshot represents? (This is usually determined from
+ * the file's header.)
+ */
+ enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled;
+
+ /*
+ * Count of references to this instance, including the pointer
+ * from `packed_ref_store::snapshot`, if any. The instance
+ * will not be freed as long as the reference count is
+ * nonzero.
+ */
+ unsigned int referrers;
+
+ /*
+ * The metadata of the `packed-refs` file from which this
+ * snapshot was created, used to tell if the file has been
+ * replaced since we read it.
+ */
+ struct stat_validity validity;
+};
/*
- * A container for `packed-refs`-related data. It is not (yet) a
- * `ref_store`.
+ * A `ref_store` representing references stored in a `packed-refs`
+ * file. It implements the `ref_store` interface, though it has some
+ * limitations:
+ *
+ * - It cannot store symbolic references.
+ *
+ * - It cannot store reflogs.
+ *
+ * - It does not support reference renaming (though it could).
+ *
+ * On the other hand, it can be locked outside of a reference
+ * transaction. In that case, it remains locked even after the
+ * transaction is done and the new `packed-refs` file is activated.
*/
struct packed_ref_store {
struct ref_store base;
char *path;
/*
- * A cache of the values read from the `packed-refs` file, if
- * it might still be current; otherwise, NULL.
+ * A snapshot of the values read from the `packed-refs` file,
+ * if it might still be current; otherwise, NULL.
*/
- struct packed_ref_cache *cache;
+ struct snapshot *snapshot;
/*
* Lock used for the "packed-refs" file. Note that this (and
struct tempfile *tempfile;
};
+/*
+ * Increment the reference count of `*snapshot`.
+ */
+static void acquire_snapshot(struct snapshot *snapshot)
+{
+ snapshot->referrers++;
+}
+
+/*
+ * If the buffer in `snapshot` is active, then either munmap the
+ * memory and close the file, or free the memory. Then set the buffer
+ * pointers to NULL.
+ */
+static void clear_snapshot_buffer(struct snapshot *snapshot)
+{
+ if (snapshot->mmapped) {
+ if (munmap(snapshot->buf, snapshot->eof - snapshot->buf))
+ die_errno("error ummapping packed-refs file %s",
+ snapshot->refs->path);
+ snapshot->mmapped = 0;
+ } else {
+ free(snapshot->buf);
+ }
+ snapshot->buf = snapshot->eof = NULL;
+ snapshot->header_len = 0;
+}
+
+/*
+ * Decrease the reference count of `*snapshot`. If it goes to zero,
+ * free `*snapshot` and return true; otherwise return false.
+ */
+static int release_snapshot(struct snapshot *snapshot)
+{
+ if (!--snapshot->referrers) {
+ stat_validity_clear(&snapshot->validity);
+ clear_snapshot_buffer(snapshot);
+ free(snapshot);
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
struct ref_store *packed_ref_store_create(const char *path,
unsigned int store_flags)
{
return refs;
}
-static void clear_packed_ref_cache(struct packed_ref_store *refs)
+static void clear_snapshot(struct packed_ref_store *refs)
{
- if (refs->cache) {
- struct packed_ref_cache *cache = refs->cache;
+ if (refs->snapshot) {
+ struct snapshot *snapshot = refs->snapshot;
- refs->cache = NULL;
- release_packed_ref_cache(cache);
+ refs->snapshot = NULL;
+ release_snapshot(snapshot);
}
}
-/* The length of a peeled reference line in packed-refs, including EOL: */
-#define PEELED_LINE_LENGTH 42
+static NORETURN void die_unterminated_line(const char *path,
+ const char *p, size_t len)
+{
+ if (len < 80)
+ die("unterminated line in %s: %.*s", path, (int)len, p);
+ else
+ die("unterminated line in %s: %.75s...", path, p);
+}
+
+static NORETURN void die_invalid_line(const char *path,
+ const char *p, size_t len)
+{
+ const char *eol = memchr(p, '\n', len);
+
+ if (!eol)
+ die_unterminated_line(path, p, len);
+ else if (eol - p < 80)
+ die("unexpected line in %s: %.*s", path, (int)(eol - p), p);
+ else
+ die("unexpected line in %s: %.75s...", path, p);
+
+}
+
+struct snapshot_record {
+ const char *start;
+ size_t len;
+};
+
+static int cmp_packed_ref_records(const void *v1, const void *v2)
+{
+ const struct snapshot_record *e1 = v1, *e2 = v2;
+ const char *r1 = e1->start + GIT_SHA1_HEXSZ + 1;
+ const char *r2 = e2->start + GIT_SHA1_HEXSZ + 1;
+
+ while (1) {
+ if (*r1 == '\n')
+ return *r2 == '\n' ? 0 : -1;
+ if (*r1 != *r2) {
+ if (*r2 == '\n')
+ return 1;
+ else
+ return (unsigned char)*r1 < (unsigned char)*r2 ? -1 : +1;
+ }
+ r1++;
+ r2++;
+ }
+}
/*
- * Parse one line from a packed-refs file. Write the SHA1 to sha1.
- * Return a pointer to the refname within the line (null-terminated),
- * or NULL if there was a problem.
+ * Compare a snapshot record at `rec` to the specified NUL-terminated
+ * refname.
*/
-static const char *parse_ref_line(struct strbuf *line, struct object_id *oid)
+static int cmp_record_to_refname(const char *rec, const char *refname)
{
- const char *ref;
+ const char *r1 = rec + GIT_SHA1_HEXSZ + 1;
+ const char *r2 = refname;
+
+ while (1) {
+ if (*r1 == '\n')
+ return *r2 ? -1 : 0;
+ if (!*r2)
+ return 1;
+ if (*r1 != *r2)
+ return (unsigned char)*r1 < (unsigned char)*r2 ? -1 : +1;
+ r1++;
+ r2++;
+ }
+}
- if (parse_oid_hex(line->buf, oid, &ref) < 0)
- return NULL;
- if (!isspace(*ref++))
- return NULL;
+/*
+ * `snapshot->buf` is not known to be sorted. Check whether it is, and
+ * if not, sort it into new memory and munmap/free the old storage.
+ */
+static void sort_snapshot(struct snapshot *snapshot)
+{
+ struct snapshot_record *records = NULL;
+ size_t alloc = 0, nr = 0;
+ int sorted = 1;
+ const char *pos, *eof, *eol;
+ size_t len, i;
+ char *new_buffer, *dst;
- if (isspace(*ref))
- return NULL;
+ pos = snapshot->buf + snapshot->header_len;
+ eof = snapshot->eof;
+ len = eof - pos;
- if (line->buf[line->len - 1] != '\n')
- return NULL;
- line->buf[--line->len] = 0;
+ if (!len)
+ return;
+
+ /*
+ * Initialize records based on a crude estimate of the number
+ * of references in the file (we'll grow it below if needed):
+ */
+ ALLOC_GROW(records, len / 80 + 20, alloc);
+
+ while (pos < eof) {
+ eol = memchr(pos, '\n', eof - pos);
+ if (!eol)
+ /* The safety check should prevent this. */
+ BUG("unterminated line found in packed-refs");
+ if (eol - pos < GIT_SHA1_HEXSZ + 2)
+ die_invalid_line(snapshot->refs->path,
+ pos, eof - pos);
+ eol++;
+ if (eol < eof && *eol == '^') {
+ /*
+ * Keep any peeled line together with its
+ * reference:
+ */
+ const char *peeled_start = eol;
+
+ eol = memchr(peeled_start, '\n', eof - peeled_start);
+ if (!eol)
+ /* The safety check should prevent this. */
+ BUG("unterminated peeled line found in packed-refs");
+ eol++;
+ }
+
+ ALLOC_GROW(records, nr + 1, alloc);
+ records[nr].start = pos;
+ records[nr].len = eol - pos;
+ nr++;
+
+ if (sorted &&
+ nr > 1 &&
+ cmp_packed_ref_records(&records[nr - 2],
+ &records[nr - 1]) >= 0)
+ sorted = 0;
+
+ pos = eol;
+ }
+
+ if (sorted)
+ goto cleanup;
+
+ /* We need to sort the memory. First we sort the records array: */
+ QSORT(records, nr, cmp_packed_ref_records);
+
+ /*
+ * Allocate a new chunk of memory, and copy the old memory to
+ * the new in the order indicated by `records` (not bothering
+ * with the header line):
+ */
+ new_buffer = xmalloc(len);
+ for (dst = new_buffer, i = 0; i < nr; i++) {
+ memcpy(dst, records[i].start, records[i].len);
+ dst += records[i].len;
+ }
+
+ /*
+ * Now munmap the old buffer and use the sorted buffer in its
+ * place:
+ */
+ clear_snapshot_buffer(snapshot);
+ snapshot->buf = new_buffer;
+ snapshot->eof = new_buffer + len;
+ snapshot->header_len = 0;
+
+cleanup:
+ free(records);
+}
+
+/*
+ * Return a pointer to the start of the record that contains the
+ * character `*p` (which must be within the buffer). If no other
+ * record start is found, return `buf`.
+ */
+static const char *find_start_of_record(const char *buf, const char *p)
+{
+ while (p > buf && (p[-1] != '\n' || p[0] == '^'))
+ p--;
+ return p;
+}
+
+/*
+ * Return a pointer to the start of the record following the record
+ * that contains `*p`. If none is found before `end`, return `end`.
+ */
+static const char *find_end_of_record(const char *p, const char *end)
+{
+ while (++p < end && (p[-1] != '\n' || p[0] == '^'))
+ ;
+ return p;
+}
+
+/*
+ * We want to be able to compare mmapped reference records quickly,
+ * without totally parsing them. We can do so because the records are
+ * LF-terminated, and the refname should start exactly (GIT_SHA1_HEXSZ
+ * + 1) bytes past the beginning of the record.
+ *
+ * But what if the `packed-refs` file contains garbage? We're willing
+ * to tolerate not detecting the problem, as long as we don't produce
+ * totally garbled output (we can't afford to check the integrity of
+ * the whole file during every Git invocation). But we do want to be
+ * sure that we never read past the end of the buffer in memory and
+ * perform an illegal memory access.
+ *
+ * Guarantee that minimum level of safety by verifying that the last
+ * record in the file is LF-terminated, and that it has at least
+ * (GIT_SHA1_HEXSZ + 1) characters before the LF. Die if either of
+ * these checks fails.
+ */
+static void verify_buffer_safe(struct snapshot *snapshot)
+{
+ const char *buf = snapshot->buf + snapshot->header_len;
+ const char *eof = snapshot->eof;
+ const char *last_line;
+
+ if (buf == eof)
+ return;
+
+ last_line = find_start_of_record(buf, eof - 1);
+ if (*(eof - 1) != '\n' || eof - last_line < GIT_SHA1_HEXSZ + 2)
+ die_invalid_line(snapshot->refs->path,
+ last_line, eof - last_line);
+}
- return ref;
+/*
+ * Depending on `mmap_strategy`, either mmap or read the contents of
+ * the `packed-refs` file into the snapshot. Return 1 if the file
+ * existed and was read, or 0 if the file was absent. Die on errors.
+ */
+static int load_contents(struct snapshot *snapshot)
+{
+ int fd;
+ struct stat st;
+ size_t size;
+ ssize_t bytes_read;
+
+ fd = open(snapshot->refs->path, O_RDONLY);
+ if (fd < 0) {
+ if (errno == ENOENT) {
+ /*
+ * This is OK; it just means that no
+ * "packed-refs" file has been written yet,
+ * which is equivalent to it being empty,
+ * which is its state when initialized with
+ * zeros.
+ */
+ return 0;
+ } else {
+ die_errno("couldn't read %s", snapshot->refs->path);
+ }
+ }
+
+ stat_validity_update(&snapshot->validity, fd);
+
+ if (fstat(fd, &st) < 0)
+ die_errno("couldn't stat %s", snapshot->refs->path);
+ size = xsize_t(st.st_size);
+
+ switch (mmap_strategy) {
+ case MMAP_NONE:
+ snapshot->buf = xmalloc(size);
+ bytes_read = read_in_full(fd, snapshot->buf, size);
+ if (bytes_read < 0 || bytes_read != size)
+ die_errno("couldn't read %s", snapshot->refs->path);
+ snapshot->eof = snapshot->buf + size;
+ snapshot->mmapped = 0;
+ break;
+ case MMAP_TEMPORARY:
+ case MMAP_OK:
+ snapshot->buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+ snapshot->eof = snapshot->buf + size;
+ snapshot->mmapped = 1;
+ break;
+ }
+ close(fd);
+
+ return 1;
}
/*
- * Read from `packed_refs_file` into a newly-allocated
- * `packed_ref_cache` and return it. The return value will already
- * have its reference count incremented.
+ * Find the place in `snapshot->buf` where the start of the record for
+ * `refname` starts. If `mustexist` is true and the reference doesn't
+ * exist, then return NULL. If `mustexist` is false and the reference
+ * doesn't exist, then return the point where that reference would be
+ * inserted. In the latter mode, `refname` doesn't have to be a proper
+ * reference name; for example, one could search for "refs/replace/"
+ * to find the start of any replace references.
+ *
+ * The record is sought using a binary search, so `snapshot->buf` must
+ * be sorted.
+ */
+static const char *find_reference_location(struct snapshot *snapshot,
+ const char *refname, int mustexist)
+{
+ /*
+ * This is not *quite* a garden-variety binary search, because
+ * the data we're searching is made up of records, and we
+ * always need to find the beginning of a record to do a
+ * comparison. A "record" here is one line for the reference
+ * itself and zero or one peel lines that start with '^'. Our
+ * loop invariant is described in the next two comments.
+ */
+
+ /*
+ * A pointer to the character at the start of a record whose
+ * preceding records all have reference names that come
+ * *before* `refname`.
+ */
+ const char *lo = snapshot->buf + snapshot->header_len;
+
+ /*
+ * A pointer to a the first character of a record whose
+ * reference name comes *after* `refname`.
+ */
+ const char *hi = snapshot->eof;
+
+ while (lo < hi) {
+ const char *mid, *rec;
+ int cmp;
+
+ mid = lo + (hi - lo) / 2;
+ rec = find_start_of_record(lo, mid);
+ cmp = cmp_record_to_refname(rec, refname);
+ if (cmp < 0) {
+ lo = find_end_of_record(mid, hi);
+ } else if (cmp > 0) {
+ hi = rec;
+ } else {
+ return rec;
+ }
+ }
+
+ if (mustexist)
+ return NULL;
+ else
+ return lo;
+}
+
+/*
+ * Create a newly-allocated `snapshot` of the `packed-refs` file in
+ * its current state and return it. The return value will already have
+ * its reference count incremented.
*
* A comment line of the form "# pack-refs with: " may contain zero or
* more traits. We interpret the traits as follows:
*
- * No traits:
+ * Neither `peeled` nor `fully-peeled`:
*
* Probably no references are peeled. But if the file contains a
* peeled value for a reference, we will use it.
*
- * peeled:
+ * `peeled`:
*
* References under "refs/tags/", if they *can* be peeled, *are*
* peeled in this file. References outside of "refs/tags/" are
* probably not peeled even if they could have been, but if we find
* a peeled value for such a reference we will use it.
*
- * fully-peeled:
+ * `fully-peeled`:
*
* All references in the file that can be peeled are peeled.
* Inversely (and this is more important), any references in the
* trait should typically be written alongside "peeled" for
* compatibility with older clients, but we do not require it
* (i.e., "peeled" is a no-op if "fully-peeled" is set).
+ *
+ * `sorted`:
+ *
+ * The references in this file are known to be sorted by refname.
*/
-static struct packed_ref_cache *read_packed_refs(const char *packed_refs_file)
+static struct snapshot *create_snapshot(struct packed_ref_store *refs)
{
- FILE *f;
- struct packed_ref_cache *packed_refs = xcalloc(1, sizeof(*packed_refs));
- struct ref_entry *last = NULL;
- struct strbuf line = STRBUF_INIT;
- enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
- struct ref_dir *dir;
-
- acquire_packed_ref_cache(packed_refs);
- packed_refs->cache = create_ref_cache(NULL, NULL);
- packed_refs->cache->root->flag &= ~REF_INCOMPLETE;
-
- f = fopen(packed_refs_file, "r");
- if (!f) {
- if (errno == ENOENT) {
- /*
- * This is OK; it just means that no
- * "packed-refs" file has been written yet,
- * which is equivalent to it being empty.
- */
- return packed_refs;
- } else {
- die_errno("couldn't read %s", packed_refs_file);
- }
- }
+ struct snapshot *snapshot = xcalloc(1, sizeof(*snapshot));
+ int sorted = 0;
- stat_validity_update(&packed_refs->validity, fileno(f));
+ snapshot->refs = refs;
+ acquire_snapshot(snapshot);
+ snapshot->peeled = PEELED_NONE;
- dir = get_ref_dir(packed_refs->cache->root);
- while (strbuf_getwholeline(&line, f, '\n') != EOF) {
- struct object_id oid;
- const char *refname;
- const char *traits;
+ if (!load_contents(snapshot))
+ return snapshot;
- if (!line.len || line.buf[line.len - 1] != '\n')
- die("unterminated line in %s: %s", packed_refs_file, line.buf);
+ /* If the file has a header line, process it: */
+ if (snapshot->buf < snapshot->eof && *snapshot->buf == '#') {
+ struct strbuf tmp = STRBUF_INIT;
+ char *p;
+ const char *eol;
+ struct string_list traits = STRING_LIST_INIT_NODUP;
- if (skip_prefix(line.buf, "# pack-refs with:", &traits)) {
- if (strstr(traits, " fully-peeled "))
- peeled = PEELED_FULLY;
- else if (strstr(traits, " peeled "))
- peeled = PEELED_TAGS;
- /* perhaps other traits later as well */
- continue;
- }
+ eol = memchr(snapshot->buf, '\n',
+ snapshot->eof - snapshot->buf);
+ if (!eol)
+ die_unterminated_line(refs->path,
+ snapshot->buf,
+ snapshot->eof - snapshot->buf);
- refname = parse_ref_line(&line, &oid);
- if (refname) {
- int flag = REF_ISPACKED;
+ strbuf_add(&tmp, snapshot->buf, eol - snapshot->buf);
- if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
- if (!refname_is_safe(refname))
- die("packed refname is dangerous: %s", refname);
- oidclr(&oid);
- flag |= REF_BAD_NAME | REF_ISBROKEN;
- }
- last = create_ref_entry(refname, &oid, flag);
- if (peeled == PEELED_FULLY ||
- (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))
- last->flag |= REF_KNOWS_PEELED;
- add_ref_entry(dir, last);
- } else if (last &&
- line.buf[0] == '^' &&
- line.len == PEELED_LINE_LENGTH &&
- line.buf[PEELED_LINE_LENGTH - 1] == '\n' &&
- !get_oid_hex(line.buf + 1, &oid)) {
- oidcpy(&last->u.value.peeled, &oid);
- /*
- * Regardless of what the file header said,
- * we definitely know the value of *this*
- * reference:
- */
- last->flag |= REF_KNOWS_PEELED;
- } else {
- strbuf_setlen(&line, line.len - 1);
- die("unexpected line in %s: %s", packed_refs_file, line.buf);
- }
+ if (!skip_prefix(tmp.buf, "# pack-refs with:", (const char **)&p))
+ die_invalid_line(refs->path,
+ snapshot->buf,
+ snapshot->eof - snapshot->buf);
+
+ string_list_split_in_place(&traits, p, ' ', -1);
+
+ if (unsorted_string_list_has_string(&traits, "fully-peeled"))
+ snapshot->peeled = PEELED_FULLY;
+ else if (unsorted_string_list_has_string(&traits, "peeled"))
+ snapshot->peeled = PEELED_TAGS;
+
+ sorted = unsorted_string_list_has_string(&traits, "sorted");
+
+ /* perhaps other traits later as well */
+
+ /* The "+ 1" is for the LF character. */
+ snapshot->header_len = eol + 1 - snapshot->buf;
+
+ string_list_clear(&traits, 0);
+ strbuf_release(&tmp);
}
- fclose(f);
- strbuf_release(&line);
+ verify_buffer_safe(snapshot);
- return packed_refs;
+ if (!sorted) {
+ sort_snapshot(snapshot);
+
+ /*
+ * Reordering the records might have moved a short one
+ * to the end of the buffer, so verify the buffer's
+ * safety again:
+ */
+ verify_buffer_safe(snapshot);
+ }
+
+ if (mmap_strategy != MMAP_OK && snapshot->mmapped) {
+ /*
+ * We don't want to leave the file mmapped, so we are
+ * forced to make a copy now:
+ */
+ size_t size = snapshot->eof -
+ (snapshot->buf + snapshot->header_len);
+ char *buf_copy = xmalloc(size);
+
+ memcpy(buf_copy, snapshot->buf + snapshot->header_len, size);
+ clear_snapshot_buffer(snapshot);
+ snapshot->buf = buf_copy;
+ snapshot->eof = buf_copy + size;
+ }
+
+ return snapshot;
}
/*
- * Check that the packed refs cache (if any) still reflects the
- * contents of the file. If not, clear the cache.
+ * Check that `refs->snapshot` (if present) still reflects the
+ * contents of the `packed-refs` file. If not, clear the snapshot.
*/
-static void validate_packed_ref_cache(struct packed_ref_store *refs)
+static void validate_snapshot(struct packed_ref_store *refs)
{
- if (refs->cache &&
- !stat_validity_check(&refs->cache->validity, refs->path))
- clear_packed_ref_cache(refs);
+ if (refs->snapshot &&
+ !stat_validity_check(&refs->snapshot->validity, refs->path))
+ clear_snapshot(refs);
}
/*
- * Get the packed_ref_cache for the specified packed_ref_store,
- * creating and populating it if it hasn't been read before or if the
- * file has been changed (according to its `validity` field) since it
- * was last read. On the other hand, if we hold the lock, then assume
- * that the file hasn't been changed out from under us, so skip the
- * extra `stat()` call in `stat_validity_check()`.
+ * Get the `snapshot` for the specified packed_ref_store, creating and
+ * populating it if it hasn't been read before or if the file has been
+ * changed (according to its `validity` field) since it was last read.
+ * On the other hand, if we hold the lock, then assume that the file
+ * hasn't been changed out from under us, so skip the extra `stat()`
+ * call in `stat_validity_check()`. This function does *not* increase
+ * the snapshot's reference count on behalf of the caller.
*/
-static struct packed_ref_cache *get_packed_ref_cache(struct packed_ref_store *refs)
+static struct snapshot *get_snapshot(struct packed_ref_store *refs)
{
if (!is_lock_file_locked(&refs->lock))
- validate_packed_ref_cache(refs);
+ validate_snapshot(refs);
- if (!refs->cache)
- refs->cache = read_packed_refs(refs->path);
+ if (!refs->snapshot)
+ refs->snapshot = create_snapshot(refs);
- return refs->cache;
-}
-
-static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
-{
- return get_ref_dir(packed_ref_cache->cache->root);
-}
-
-static struct ref_dir *get_packed_refs(struct packed_ref_store *refs)
-{
- return get_packed_ref_dir(get_packed_ref_cache(refs));
-}
-
-/*
- * Return the ref_entry for the given refname from the packed
- * references. If it does not exist, return NULL.
- */
-static struct ref_entry *get_packed_ref(struct packed_ref_store *refs,
- const char *refname)
-{
- return find_ref_entry(get_packed_refs(refs), refname);
+ return refs->snapshot;
}
static int packed_read_raw_ref(struct ref_store *ref_store,
{
struct packed_ref_store *refs =
packed_downcast(ref_store, REF_STORE_READ, "read_raw_ref");
-
- struct ref_entry *entry;
+ struct snapshot *snapshot = get_snapshot(refs);
+ const char *rec;
*type = 0;
- entry = get_packed_ref(refs, refname);
- if (!entry) {
+ rec = find_reference_location(snapshot, refname, 1);
+
+ if (!rec) {
+ /* refname is not a packed reference. */
errno = ENOENT;
return -1;
}
- hashcpy(sha1, entry->u.value.oid.hash);
+ if (get_sha1_hex(rec, sha1))
+ die_invalid_line(refs->path, rec, snapshot->eof - rec);
+
*type = REF_ISPACKED;
return 0;
}
-static int packed_peel_ref(struct ref_store *ref_store,
- const char *refname, unsigned char *sha1)
-{
- struct packed_ref_store *refs =
- packed_downcast(ref_store, REF_STORE_READ | REF_STORE_ODB,
- "peel_ref");
- struct ref_entry *r = get_packed_ref(refs, refname);
-
- if (!r || peel_entry(r, 0))
- return -1;
-
- hashcpy(sha1, r->u.value.peeled.hash);
- return 0;
-}
+/*
+ * This value is set in `base.flags` if the peeled value of the
+ * current reference is known. In that case, `peeled` contains the
+ * correct peeled value for the reference, which might be `null_sha1`
+ * if the reference is not a tag or if it is broken.
+ */
+#define REF_KNOWS_PEELED 0x40
+/*
+ * An iterator over a snapshot of a `packed-refs` file.
+ */
struct packed_ref_iterator {
struct ref_iterator base;
- struct packed_ref_cache *cache;
- struct ref_iterator *iter0;
+ struct snapshot *snapshot;
+
+ /* The current position in the snapshot's buffer: */
+ const char *pos;
+
+ /* The end of the part of the buffer that will be iterated over: */
+ const char *eof;
+
+ /* Scratch space for current values: */
+ struct object_id oid, peeled;
+ struct strbuf refname_buf;
+
unsigned int flags;
};
+/*
+ * Move the iterator to the next record in the snapshot, without
+ * respect for whether the record is actually required by the current
+ * iteration. Adjust the fields in `iter` and return `ITER_OK` or
+ * `ITER_DONE`. This function does not free the iterator in the case
+ * of `ITER_DONE`.
+ */
+static int next_record(struct packed_ref_iterator *iter)
+{
+ const char *p = iter->pos, *eol;
+
+ strbuf_reset(&iter->refname_buf);
+
+ if (iter->pos == iter->eof)
+ return ITER_DONE;
+
+ iter->base.flags = REF_ISPACKED;
+
+ if (iter->eof - p < GIT_SHA1_HEXSZ + 2 ||
+ parse_oid_hex(p, &iter->oid, &p) ||
+ !isspace(*p++))
+ die_invalid_line(iter->snapshot->refs->path,
+ iter->pos, iter->eof - iter->pos);
+
+ eol = memchr(p, '\n', iter->eof - p);
+ if (!eol)
+ die_unterminated_line(iter->snapshot->refs->path,
+ iter->pos, iter->eof - iter->pos);
+
+ strbuf_add(&iter->refname_buf, p, eol - p);
+ iter->base.refname = iter->refname_buf.buf;
+
+ if (check_refname_format(iter->base.refname, REFNAME_ALLOW_ONELEVEL)) {
+ if (!refname_is_safe(iter->base.refname))
+ die("packed refname is dangerous: %s",
+ iter->base.refname);
+ oidclr(&iter->oid);
+ iter->base.flags |= REF_BAD_NAME | REF_ISBROKEN;
+ }
+ if (iter->snapshot->peeled == PEELED_FULLY ||
+ (iter->snapshot->peeled == PEELED_TAGS &&
+ starts_with(iter->base.refname, "refs/tags/")))
+ iter->base.flags |= REF_KNOWS_PEELED;
+
+ iter->pos = eol + 1;
+
+ if (iter->pos < iter->eof && *iter->pos == '^') {
+ p = iter->pos + 1;
+ if (iter->eof - p < GIT_SHA1_HEXSZ + 1 ||
+ parse_oid_hex(p, &iter->peeled, &p) ||
+ *p++ != '\n')
+ die_invalid_line(iter->snapshot->refs->path,
+ iter->pos, iter->eof - iter->pos);
+ iter->pos = p;
+
+ /*
+ * Regardless of what the file header said, we
+ * definitely know the value of *this* reference. But
+ * we suppress it if the reference is broken:
+ */
+ if ((iter->base.flags & REF_ISBROKEN)) {
+ oidclr(&iter->peeled);
+ iter->base.flags &= ~REF_KNOWS_PEELED;
+ } else {
+ iter->base.flags |= REF_KNOWS_PEELED;
+ }
+ } else {
+ oidclr(&iter->peeled);
+ }
+
+ return ITER_OK;
+}
+
static int packed_ref_iterator_advance(struct ref_iterator *ref_iterator)
{
struct packed_ref_iterator *iter =
(struct packed_ref_iterator *)ref_iterator;
int ok;
- while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {
+ while ((ok = next_record(iter)) == ITER_OK) {
if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&
- ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)
+ ref_type(iter->base.refname) != REF_TYPE_PER_WORKTREE)
continue;
if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
- !ref_resolves_to_object(iter->iter0->refname,
- iter->iter0->oid,
- iter->iter0->flags))
+ !ref_resolves_to_object(iter->base.refname, &iter->oid,
+ iter->flags))
continue;
- iter->base.refname = iter->iter0->refname;
- iter->base.oid = iter->iter0->oid;
- iter->base.flags = iter->iter0->flags;
return ITER_OK;
}
- iter->iter0 = NULL;
if (ref_iterator_abort(ref_iterator) != ITER_DONE)
ok = ITER_ERROR;
struct packed_ref_iterator *iter =
(struct packed_ref_iterator *)ref_iterator;
- return ref_iterator_peel(iter->iter0, peeled);
+ if ((iter->base.flags & REF_KNOWS_PEELED)) {
+ oidcpy(peeled, &iter->peeled);
+ return is_null_oid(&iter->peeled) ? -1 : 0;
+ } else if ((iter->base.flags & (REF_ISBROKEN | REF_ISSYMREF))) {
+ return -1;
+ } else {
+ return !!peel_object(iter->oid.hash, peeled->hash);
+ }
}
static int packed_ref_iterator_abort(struct ref_iterator *ref_iterator)
(struct packed_ref_iterator *)ref_iterator;
int ok = ITER_DONE;
- if (iter->iter0)
- ok = ref_iterator_abort(iter->iter0);
-
- release_packed_ref_cache(iter->cache);
+ strbuf_release(&iter->refname_buf);
+ release_snapshot(iter->snapshot);
base_ref_iterator_free(ref_iterator);
return ok;
}
const char *prefix, unsigned int flags)
{
struct packed_ref_store *refs;
+ struct snapshot *snapshot;
+ const char *start;
struct packed_ref_iterator *iter;
struct ref_iterator *ref_iterator;
unsigned int required_flags = REF_STORE_READ;
required_flags |= REF_STORE_ODB;
refs = packed_downcast(ref_store, required_flags, "ref_iterator_begin");
+ /*
+ * Note that `get_snapshot()` internally checks whether the
+ * snapshot is up to date with what is on disk, and re-reads
+ * it if not.
+ */
+ snapshot = get_snapshot(refs);
+
+ if (!snapshot->buf)
+ return empty_ref_iterator_begin();
+
iter = xcalloc(1, sizeof(*iter));
ref_iterator = &iter->base;
- base_ref_iterator_init(ref_iterator, &packed_ref_iterator_vtable);
+ base_ref_iterator_init(ref_iterator, &packed_ref_iterator_vtable, 1);
- /*
- * Note that get_packed_ref_cache() internally checks whether
- * the packed-ref cache is up to date with what is on disk,
- * and re-reads it if not.
- */
+ iter->snapshot = snapshot;
+ acquire_snapshot(snapshot);
- iter->cache = get_packed_ref_cache(refs);
- acquire_packed_ref_cache(iter->cache);
- iter->iter0 = cache_ref_iterator_begin(iter->cache->cache, prefix, 0);
+ if (prefix && *prefix)
+ start = find_reference_location(snapshot, prefix, 0);
+ else
+ start = snapshot->buf + snapshot->header_len;
+
+ iter->pos = start;
+ iter->eof = snapshot->eof;
+ strbuf_init(&iter->refname_buf, 0);
+
+ iter->base.oid = &iter->oid;
iter->flags = flags;
+ if (prefix && *prefix)
+ /* Stop iteration after we've gone *past* prefix: */
+ ref_iterator = prefix_ref_iterator_begin(ref_iterator, prefix, 0);
+
return ref_iterator;
}
/*
* Now that we hold the `packed-refs` lock, make sure that our
- * cache matches the current version of the file. Normally
- * `get_packed_ref_cache()` does that for us, but that
- * function assumes that when the file is locked, any existing
- * cache is still valid. We've just locked the file, but it
- * might have changed the moment *before* we locked it.
+ * snapshot matches the current version of the file. Normally
+ * `get_snapshot()` does that for us, but that function
+ * assumes that when the file is locked, any existing snapshot
+ * is still valid. We've just locked the file, but it might
+ * have changed the moment *before* we locked it.
*/
- validate_packed_ref_cache(refs);
+ validate_snapshot(refs);
/*
* Now make sure that the packed-refs file as it exists in the
- * locked state is loaded into the cache:
+ * locked state is loaded into the snapshot:
*/
- get_packed_ref_cache(refs);
+ get_snapshot(refs);
return 0;
}
}
/*
- * The packed-refs header line that we write out. Perhaps other
- * traits will be added later. The trailing space is required.
+ * The packed-refs header line that we write out. Perhaps other traits
+ * will be added later.
+ *
+ * Note that earlier versions of Git used to parse these traits by
+ * looking for " trait " in the line. For this reason, the space after
+ * the colon and the trailing space are required.
*/
static const char PACKED_REFS_HEADER[] =
- "# pack-refs with: peeled fully-peeled \n";
+ "# pack-refs with: peeled fully-peeled sorted \n";
static int packed_init_db(struct ref_store *ref_store, struct strbuf *err)
{
}
/*
- * Write the packed-refs from the cache to the packed-refs tempfile,
- * incorporating any changes from `updates`. `updates` must be a
- * sorted string list whose keys are the refnames and whose util
+ * Write the packed refs from the current snapshot to the packed-refs
+ * tempfile, incorporating any changes from `updates`. `updates` must
+ * be a sorted string list whose keys are the refnames and whose util
* values are `struct ref_update *`. On error, rollback the tempfile,
* write an error message to `err`, and return a nonzero value.
*
}
if (ok != ITER_DONE) {
- strbuf_addf(err, "unable to write packed-refs file: "
- "error iterating over old contents");
+ strbuf_addstr(err, "unable to write packed-refs file: "
+ "error iterating over old contents");
goto error;
}
/*
* Note that we *don't* skip transactions with zero updates,
* because such a transaction might be executed for the side
- * effect of ensuring that all of the references are peeled.
- * If the caller wants to optimize away empty transactions, it
- * should do so itself.
+ * effect of ensuring that all of the references are peeled or
+ * ensuring that the `packed-refs` file is sorted. If the
+ * caller wants to optimize away empty transactions, it should
+ * do so itself.
*/
data = xcalloc(1, sizeof(*data));
int ret = TRANSACTION_GENERIC_ERROR;
char *packed_refs_path;
+ clear_snapshot(refs);
+
packed_refs_path = get_locked_file_path(&refs->lock);
if (rename_tempfile(&refs->tempfile, packed_refs_path)) {
strbuf_addf(err, "error replacing %s: %s",
goto cleanup;
}
- clear_packed_ref_cache(refs);
ret = 0;
cleanup:
die("BUG: packed reference store does not support renaming references");
}
+static int packed_copy_ref(struct ref_store *ref_store,
+ const char *oldrefname, const char *newrefname,
+ const char *logmsg)
+{
+ die("BUG: packed reference store does not support copying references");
+}
+
static struct ref_iterator *packed_reflog_iterator_begin(struct ref_store *ref_store)
{
return empty_ref_iterator_begin();
packed_initial_transaction_commit,
packed_pack_refs,
- packed_peel_ref,
packed_create_symref,
packed_delete_refs,
packed_rename_ref,
+ packed_copy_ref,
packed_ref_iterator_begin,
packed_read_raw_ref,
#include "trailer.h"
#include "log-tree.h"
#include "wt-status.h"
+#include "hashmap.h"
#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
free(opts->xopts[i]);
free(opts->xopts);
- strbuf_addf(&dir, "%s", get_dir(opts));
+ strbuf_addstr(&dir, get_dir(opts));
remove_dir_recursively(&dir, 0);
strbuf_release(&dir);
strbuf_release(&sob);
}
+
+int sequencer_make_script(int keep_empty, FILE *out,
+ int argc, const char **argv)
+{
+ char *format = NULL;
+ struct pretty_print_context pp = {0};
+ struct strbuf buf = STRBUF_INIT;
+ struct rev_info revs;
+ struct commit *commit;
+
+ init_revisions(&revs, NULL);
+ revs.verbose_header = 1;
+ revs.max_parents = 1;
+ revs.cherry_pick = 1;
+ revs.limited = 1;
+ revs.reverse = 1;
+ revs.right_only = 1;
+ revs.sort_order = REV_SORT_IN_GRAPH_ORDER;
+ revs.topo_order = 1;
+
+ revs.pretty_given = 1;
+ git_config_get_string("rebase.instructionFormat", &format);
+ if (!format || !*format) {
+ free(format);
+ format = xstrdup("%s");
+ }
+ get_commit_format(format, &revs);
+ free(format);
+ pp.fmt = revs.commit_format;
+ pp.output_encoding = get_log_output_encoding();
+
+ if (setup_revisions(argc, argv, &revs, NULL) > 1)
+ return error(_("make_script: unhandled options"));
+
+ if (prepare_revision_walk(&revs) < 0)
+ return error(_("make_script: error preparing revisions"));
+
+ while ((commit = get_revision(&revs))) {
+ strbuf_reset(&buf);
+ if (!keep_empty && is_original_commit_empty(commit))
+ strbuf_addf(&buf, "%c ", comment_line_char);
+ strbuf_addf(&buf, "pick %s ", oid_to_hex(&commit->object.oid));
+ pretty_print_commit(&pp, commit, &buf);
+ strbuf_addch(&buf, '\n');
+ fputs(buf.buf, out);
+ }
+ strbuf_release(&buf);
+ return 0;
+}
+
+
+int transform_todo_ids(int shorten_ids)
+{
+ const char *todo_file = rebase_path_todo();
+ struct todo_list todo_list = TODO_LIST_INIT;
+ int fd, res, i;
+ FILE *out;
+
+ strbuf_reset(&todo_list.buf);
+ fd = open(todo_file, O_RDONLY);
+ if (fd < 0)
+ return error_errno(_("could not open '%s'"), todo_file);
+ if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
+ close(fd);
+ return error(_("could not read '%s'."), todo_file);
+ }
+ close(fd);
+
+ res = parse_insn_buffer(todo_list.buf.buf, &todo_list);
+ if (res) {
+ todo_list_release(&todo_list);
+ return error(_("unusable todo list: '%s'"), todo_file);
+ }
+
+ out = fopen(todo_file, "w");
+ if (!out) {
+ todo_list_release(&todo_list);
+ return error(_("unable to open '%s' for writing"), todo_file);
+ }
+ for (i = 0; i < todo_list.nr; i++) {
+ struct todo_item *item = todo_list.items + i;
+ int bol = item->offset_in_buf;
+ const char *p = todo_list.buf.buf + bol;
+ int eol = i + 1 < todo_list.nr ?
+ todo_list.items[i + 1].offset_in_buf :
+ todo_list.buf.len;
+
+ if (item->command >= TODO_EXEC && item->command != TODO_DROP)
+ fwrite(p, eol - bol, 1, out);
+ else {
+ const char *id = shorten_ids ?
+ short_commit_name(item->commit) :
+ oid_to_hex(&item->commit->object.oid);
+ int len;
+
+ p += strspn(p, " \t"); /* left-trim command */
+ len = strcspn(p, " \t"); /* length of command */
+
+ fprintf(out, "%.*s %s %.*s\n",
+ len, p, id, item->arg_len, item->arg);
+ }
+ }
+ fclose(out);
+ todo_list_release(&todo_list);
+ return 0;
+}
+
+enum check_level {
+ CHECK_IGNORE = 0, CHECK_WARN, CHECK_ERROR
+};
+
+static enum check_level get_missing_commit_check_level(void)
+{
+ const char *value;
+
+ if (git_config_get_value("rebase.missingcommitscheck", &value) ||
+ !strcasecmp("ignore", value))
+ return CHECK_IGNORE;
+ if (!strcasecmp("warn", value))
+ return CHECK_WARN;
+ if (!strcasecmp("error", value))
+ return CHECK_ERROR;
+ warning(_("unrecognized setting %s for option"
+ "rebase.missingCommitsCheck. Ignoring."), value);
+ return CHECK_IGNORE;
+}
+
+/*
+ * Check if the user dropped some commits by mistake
+ * Behaviour determined by rebase.missingCommitsCheck.
+ * Check if there is an unrecognized command or a
+ * bad SHA-1 in a command.
+ */
+int check_todo_list(void)
+{
+ enum check_level check_level = get_missing_commit_check_level();
+ struct strbuf todo_file = STRBUF_INIT;
+ struct todo_list todo_list = TODO_LIST_INIT;
+ struct strbuf missing = STRBUF_INIT;
+ int advise_to_edit_todo = 0, res = 0, fd, i;
+
+ strbuf_addstr(&todo_file, rebase_path_todo());
+ fd = open(todo_file.buf, O_RDONLY);
+ if (fd < 0) {
+ res = error_errno(_("could not open '%s'"), todo_file.buf);
+ goto leave_check;
+ }
+ if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
+ close(fd);
+ res = error(_("could not read '%s'."), todo_file.buf);
+ goto leave_check;
+ }
+ close(fd);
+ advise_to_edit_todo = res =
+ parse_insn_buffer(todo_list.buf.buf, &todo_list);
+
+ if (res || check_level == CHECK_IGNORE)
+ goto leave_check;
+
+ /* Mark the commits in git-rebase-todo as seen */
+ for (i = 0; i < todo_list.nr; i++) {
+ struct commit *commit = todo_list.items[i].commit;
+ if (commit)
+ commit->util = (void *)1;
+ }
+
+ todo_list_release(&todo_list);
+ strbuf_addstr(&todo_file, ".backup");
+ fd = open(todo_file.buf, O_RDONLY);
+ if (fd < 0) {
+ res = error_errno(_("could not open '%s'"), todo_file.buf);
+ goto leave_check;
+ }
+ if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
+ close(fd);
+ res = error(_("could not read '%s'."), todo_file.buf);
+ goto leave_check;
+ }
+ close(fd);
+ strbuf_release(&todo_file);
+ res = !!parse_insn_buffer(todo_list.buf.buf, &todo_list);
+
+ /* Find commits in git-rebase-todo.backup yet unseen */
+ for (i = todo_list.nr - 1; i >= 0; i--) {
+ struct todo_item *item = todo_list.items + i;
+ struct commit *commit = item->commit;
+ if (commit && !commit->util) {
+ strbuf_addf(&missing, " - %s %.*s\n",
+ short_commit_name(commit),
+ item->arg_len, item->arg);
+ commit->util = (void *)1;
+ }
+ }
+
+ /* Warn about missing commits */
+ if (!missing.len)
+ goto leave_check;
+
+ if (check_level == CHECK_ERROR)
+ advise_to_edit_todo = res = 1;
+
+ fprintf(stderr,
+ _("Warning: some commits may have been dropped accidentally.\n"
+ "Dropped commits (newer to older):\n"));
+
+ /* Make the list user-friendly and display */
+ fputs(missing.buf, stderr);
+ strbuf_release(&missing);
+
+ fprintf(stderr, _("To avoid this message, use \"drop\" to "
+ "explicitly remove a commit.\n\n"
+ "Use 'git config rebase.missingCommitsCheck' to change "
+ "the level of warnings.\n"
+ "The possible behaviours are: ignore, warn, error.\n\n"));
+
+leave_check:
+ strbuf_release(&todo_file);
+ todo_list_release(&todo_list);
+
+ if (advise_to_edit_todo)
+ fprintf(stderr,
+ _("You can fix this with 'git rebase --edit-todo' "
+ "and then run 'git rebase --continue'.\n"
+ "Or you can abort the rebase with 'git rebase"
+ " --abort'.\n"));
+
+ return res;
+}
+
+/* skip picking commits whose parents are unchanged */
+int skip_unnecessary_picks(void)
+{
+ const char *todo_file = rebase_path_todo();
+ struct strbuf buf = STRBUF_INIT;
+ struct todo_list todo_list = TODO_LIST_INIT;
+ struct object_id onto_oid, *oid = &onto_oid, *parent_oid;
+ int fd, i;
+
+ if (!read_oneliner(&buf, rebase_path_onto(), 0))
+ return error(_("could not read 'onto'"));
+ if (get_oid(buf.buf, &onto_oid)) {
+ strbuf_release(&buf);
+ return error(_("need a HEAD to fixup"));
+ }
+ strbuf_release(&buf);
+
+ fd = open(todo_file, O_RDONLY);
+ if (fd < 0) {
+ return error_errno(_("could not open '%s'"), todo_file);
+ }
+ if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
+ close(fd);
+ return error(_("could not read '%s'."), todo_file);
+ }
+ close(fd);
+ if (parse_insn_buffer(todo_list.buf.buf, &todo_list) < 0) {
+ todo_list_release(&todo_list);
+ return -1;
+ }
+
+ for (i = 0; i < todo_list.nr; i++) {
+ struct todo_item *item = todo_list.items + i;
+
+ if (item->command >= TODO_NOOP)
+ continue;
+ if (item->command != TODO_PICK)
+ break;
+ if (parse_commit(item->commit)) {
+ todo_list_release(&todo_list);
+ return error(_("could not parse commit '%s'"),
+ oid_to_hex(&item->commit->object.oid));
+ }
+ if (!item->commit->parents)
+ break; /* root commit */
+ if (item->commit->parents->next)
+ break; /* merge commit */
+ parent_oid = &item->commit->parents->item->object.oid;
+ if (hashcmp(parent_oid->hash, oid->hash))
+ break;
+ oid = &item->commit->object.oid;
+ }
+ if (i > 0) {
+ int offset = i < todo_list.nr ?
+ todo_list.items[i].offset_in_buf : todo_list.buf.len;
+ const char *done_path = rebase_path_done();
+
+ fd = open(done_path, O_CREAT | O_WRONLY | O_APPEND, 0666);
+ if (fd < 0) {
+ error_errno(_("could not open '%s' for writing"),
+ done_path);
+ todo_list_release(&todo_list);
+ return -1;
+ }
+ if (write_in_full(fd, todo_list.buf.buf, offset) < 0) {
+ error_errno(_("could not write to '%s'"), done_path);
+ todo_list_release(&todo_list);
+ close(fd);
+ return -1;
+ }
+ close(fd);
+
+ fd = open(rebase_path_todo(), O_WRONLY, 0666);
+ if (fd < 0) {
+ error_errno(_("could not open '%s' for writing"),
+ rebase_path_todo());
+ todo_list_release(&todo_list);
+ return -1;
+ }
+ if (write_in_full(fd, todo_list.buf.buf + offset,
+ todo_list.buf.len - offset) < 0) {
+ error_errno(_("could not write to '%s'"),
+ rebase_path_todo());
+ close(fd);
+ todo_list_release(&todo_list);
+ return -1;
+ }
+ if (ftruncate(fd, todo_list.buf.len - offset) < 0) {
+ error_errno(_("could not truncate '%s'"),
+ rebase_path_todo());
+ todo_list_release(&todo_list);
+ close(fd);
+ return -1;
+ }
+ close(fd);
+
+ todo_list.current = i;
+ if (is_fixup(peek_command(&todo_list, 0)))
+ record_in_rewritten(oid, peek_command(&todo_list, 0));
+ }
+
+ todo_list_release(&todo_list);
+ printf("%s\n", oid_to_hex(oid));
+
+ return 0;
+}
+
+struct subject2item_entry {
+ struct hashmap_entry entry;
+ int i;
+ char subject[FLEX_ARRAY];
+};
+
+static int subject2item_cmp(const void *fndata,
+ const struct subject2item_entry *a,
+ const struct subject2item_entry *b, const void *key)
+{
+ return key ? strcmp(a->subject, key) : strcmp(a->subject, b->subject);
+}
+
+/*
+ * Rearrange the todo list that has both "pick commit-id msg" and "pick
+ * commit-id fixup!/squash! msg" in it so that the latter is put immediately
+ * after the former, and change "pick" to "fixup"/"squash".
+ *
+ * Note that if the config has specified a custom instruction format, each log
+ * message will have to be retrieved from the commit (as the oneline in the
+ * script cannot be trusted) in order to normalize the autosquash arrangement.
+ */
+int rearrange_squash(void)
+{
+ const char *todo_file = rebase_path_todo();
+ struct todo_list todo_list = TODO_LIST_INIT;
+ struct hashmap subject2item;
+ int res = 0, rearranged = 0, *next, *tail, fd, i;
+ char **subjects;
+
+ fd = open(todo_file, O_RDONLY);
+ if (fd < 0)
+ return error_errno(_("could not open '%s'"), todo_file);
+ if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
+ close(fd);
+ return error(_("could not read '%s'."), todo_file);
+ }
+ close(fd);
+ if (parse_insn_buffer(todo_list.buf.buf, &todo_list) < 0) {
+ todo_list_release(&todo_list);
+ return -1;
+ }
+
+ /*
+ * The hashmap maps onelines to the respective todo list index.
+ *
+ * If any items need to be rearranged, the next[i] value will indicate
+ * which item was moved directly after the i'th.
+ *
+ * In that case, last[i] will indicate the index of the latest item to
+ * be moved to appear after the i'th.
+ */
+ hashmap_init(&subject2item, (hashmap_cmp_fn) subject2item_cmp,
+ NULL, todo_list.nr);
+ ALLOC_ARRAY(next, todo_list.nr);
+ ALLOC_ARRAY(tail, todo_list.nr);
+ ALLOC_ARRAY(subjects, todo_list.nr);
+ for (i = 0; i < todo_list.nr; i++) {
+ struct strbuf buf = STRBUF_INIT;
+ struct todo_item *item = todo_list.items + i;
+ const char *commit_buffer, *subject, *p;
+ size_t subject_len;
+ int i2 = -1;
+ struct subject2item_entry *entry;
+
+ next[i] = tail[i] = -1;
+ if (item->command >= TODO_EXEC) {
+ subjects[i] = NULL;
+ continue;
+ }
+
+ if (is_fixup(item->command)) {
+ todo_list_release(&todo_list);
+ return error(_("the script was already rearranged."));
+ }
+
+ item->commit->util = item;
+
+ parse_commit(item->commit);
+ commit_buffer = get_commit_buffer(item->commit, NULL);
+ find_commit_subject(commit_buffer, &subject);
+ format_subject(&buf, subject, " ");
+ subject = subjects[i] = strbuf_detach(&buf, &subject_len);
+ unuse_commit_buffer(item->commit, commit_buffer);
+ if ((skip_prefix(subject, "fixup! ", &p) ||
+ skip_prefix(subject, "squash! ", &p))) {
+ struct commit *commit2;
+
+ for (;;) {
+ while (isspace(*p))
+ p++;
+ if (!skip_prefix(p, "fixup! ", &p) &&
+ !skip_prefix(p, "squash! ", &p))
+ break;
+ }
+
+ if ((entry = hashmap_get_from_hash(&subject2item,
+ strhash(p), p)))
+ /* found by title */
+ i2 = entry->i;
+ else if (!strchr(p, ' ') &&
+ (commit2 =
+ lookup_commit_reference_by_name(p)) &&
+ commit2->util)
+ /* found by commit name */
+ i2 = (struct todo_item *)commit2->util
+ - todo_list.items;
+ else {
+ /* copy can be a prefix of the commit subject */
+ for (i2 = 0; i2 < i; i2++)
+ if (subjects[i2] &&
+ starts_with(subjects[i2], p))
+ break;
+ if (i2 == i)
+ i2 = -1;
+ }
+ }
+ if (i2 >= 0) {
+ rearranged = 1;
+ todo_list.items[i].command =
+ starts_with(subject, "fixup!") ?
+ TODO_FIXUP : TODO_SQUASH;
+ if (next[i2] < 0)
+ next[i2] = i;
+ else
+ next[tail[i2]] = i;
+ tail[i2] = i;
+ } else if (!hashmap_get_from_hash(&subject2item,
+ strhash(subject), subject)) {
+ FLEX_ALLOC_MEM(entry, subject, subject, subject_len);
+ entry->i = i;
+ hashmap_entry_init(entry, strhash(entry->subject));
+ hashmap_put(&subject2item, entry);
+ }
+ }
+
+ if (rearranged) {
+ struct strbuf buf = STRBUF_INIT;
+
+ for (i = 0; i < todo_list.nr; i++) {
+ enum todo_command command = todo_list.items[i].command;
+ int cur = i;
+
+ /*
+ * Initially, all commands are 'pick's. If it is a
+ * fixup or a squash now, we have rearranged it.
+ */
+ if (is_fixup(command))
+ continue;
+
+ while (cur >= 0) {
+ int offset = todo_list.items[cur].offset_in_buf;
+ int end_offset = cur + 1 < todo_list.nr ?
+ todo_list.items[cur + 1].offset_in_buf :
+ todo_list.buf.len;
+ char *bol = todo_list.buf.buf + offset;
+ char *eol = todo_list.buf.buf + end_offset;
+
+ /* replace 'pick', by 'fixup' or 'squash' */
+ command = todo_list.items[cur].command;
+ if (is_fixup(command)) {
+ strbuf_addstr(&buf,
+ todo_command_info[command].str);
+ bol += strcspn(bol, " \t");
+ }
+
+ strbuf_add(&buf, bol, eol - bol);
+
+ cur = next[cur];
+ }
+ }
+
+ fd = open(todo_file, O_WRONLY);
+ if (fd < 0)
+ res = error_errno(_("could not open '%s'"), todo_file);
+ else if (write(fd, buf.buf, buf.len) < 0)
+ res = error_errno(_("could not read '%s'."), todo_file);
+ else if (ftruncate(fd, buf.len) < 0)
+ res = error_errno(_("could not finish '%s'"),
+ todo_file);
+ close(fd);
+ strbuf_release(&buf);
+ }
+
+ free(next);
+ free(tail);
+ for (i = 0; i < todo_list.nr; i++)
+ free(subjects[i]);
+ free(subjects);
+ hashmap_free(&subject2item, 1);
+ todo_list_release(&todo_list);
+
+ return res;
+}