encode short deltas in memory instead of writing them to a temporary file
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diff --git a/lib/pack_create.c b/lib/pack_create.c
index 7342a8a..f9ef76e 100644
--- a/lib/pack_create.c
+++ b/lib/pack_create.c
@@ -69,8 +69,9 @@ struct got_pack_meta {
/* The best delta we picked */
struct got_pack_meta *head;
struct got_pack_meta *prev;
+ unsigned char *delta_buf; /* if not encoded in delta cache file */
off_t delta_offset; /* offset in delta cache file */
- off_t delta_len; /* length in delta cache file */
+ off_t delta_len; /* encoded delta length */
int nchain;
/* Only used for delta window */
@@ -121,6 +122,8 @@ clear_meta(struct got_pack_meta *meta)
return;
free(meta->path);
meta->path = NULL;
+ free(meta->delta_buf);
+ meta->delta_buf = NULL;
}
static void
@@ -152,10 +155,11 @@ delta_order_cmp(const void *pa, const void *pb)
return got_object_id_cmp(&a->id, &b->id);
}
-static int
+static off_t
delta_size(struct got_delta_instruction *deltas, int ndeltas)
{
- int i, size = 32;
+ int i;
+ off_t size = 32;
for (i = 0; i < ndeltas; i++) {
if (deltas[i].copy)
size += GOT_DELTA_SIZE_SHIFT;
@@ -166,6 +170,135 @@ delta_size(struct got_delta_instruction *deltas, int ndeltas)
}
static const struct got_error *
+append(unsigned char **p, size_t *len, off_t *sz, void *seg, int nseg)
+{
+ char *n;
+
+ if (*len + nseg >= *sz) {
+ while (*len + nseg >= *sz)
+ *sz += *sz / 2;
+ n = realloc(*p, *sz);
+ if (n == NULL)
+ return got_error_from_errno("realloc");
+ *p = n;
+ }
+ memcpy(*p + *len, seg, nseg);
+ *len += nseg;
+ return NULL;
+}
+
+static const struct got_error *
+encode_delta_in_mem(struct got_pack_meta *m, struct got_raw_object *o,
+ struct got_delta_instruction *deltas, int ndeltas,
+ off_t delta_size, off_t base_size)
+{
+ const struct got_error *err;
+ unsigned char buf[16], *bp;
+ int i, j;
+ size_t len = 0;
+ off_t n;
+ struct got_delta_instruction *d;
+
+ m->delta_buf = malloc(delta_size);
+ if (m->delta_buf == NULL)
+ return got_error_from_errno("calloc");
+
+ /* base object size */
+ buf[0] = base_size & GOT_DELTA_SIZE_VAL_MASK;
+ n = base_size >> GOT_DELTA_SIZE_SHIFT;
+ for (i = 1; n > 0; i++) {
+ buf[i - 1] |= GOT_DELTA_SIZE_MORE;
+ buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
+ n >>= GOT_DELTA_SIZE_SHIFT;
+ }
+ err = append(&m->delta_buf, &len, &delta_size, buf, i);
+ if (err)
+ return err;
+
+ /* target object size */
+ buf[0] = o->size & GOT_DELTA_SIZE_VAL_MASK;
+ n = o->size >> GOT_DELTA_SIZE_SHIFT;
+ for (i = 1; n > 0; i++) {
+ buf[i - 1] |= GOT_DELTA_SIZE_MORE;
+ buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
+ n >>= GOT_DELTA_SIZE_SHIFT;
+ }
+ err = append(&m->delta_buf, &len, &delta_size, buf, i);
+ if (err)
+ return err;
+
+ for (j = 0; j < ndeltas; j++) {
+ d = &deltas[j];
+ if (d->copy) {
+ n = d->offset;
+ bp = &buf[1];
+ buf[0] = GOT_DELTA_BASE_COPY;
+ for (i = 0; i < 4; i++) {
+ /* DELTA_COPY_OFF1 ... DELTA_COPY_OFF4 */
+ buf[0] |= 1 << i;
+ *bp++ = n & 0xff;
+ n >>= 8;
+ if (n == 0)
+ break;
+ }
+
+ n = d->len;
+ if (n != GOT_DELTA_COPY_DEFAULT_LEN) {
+ /* DELTA_COPY_LEN1 ... DELTA_COPY_LEN3 */
+ for (i = 0; i < 3 && n > 0; i++) {
+ buf[0] |= 1 << (i + 4);
+ *bp++ = n & 0xff;
+ n >>= 8;
+ }
+ }
+ err = append(&m->delta_buf, &len, &delta_size,
+ buf, bp - buf);
+ if (err)
+ return err;
+ } else if (o->f == NULL) {
+ n = 0;
+ while (n != d->len) {
+ buf[0] = (d->len - n < 127) ? d->len - n : 127;
+ err = append(&m->delta_buf, &len, &delta_size,
+ buf, 1);
+ if (err)
+ return err;
+ err = append(&m->delta_buf, &len, &delta_size,
+ o->data + o->hdrlen + d->offset + n,
+ buf[0]);
+ if (err)
+ return err;
+ n += buf[0];
+ }
+ } else {
+ char content[128];
+ size_t r;
+ if (fseeko(o->f, o->hdrlen + d->offset, SEEK_SET) == -1)
+ return got_error_from_errno("fseeko");
+ n = 0;
+ while (n != d->len) {
+ buf[0] = (d->len - n < 127) ? d->len - n : 127;
+ err = append(&m->delta_buf, &len, &delta_size,
+ buf, 1);
+ if (err)
+ return err;
+ r = fread(content, 1, buf[0], o->f);
+ if (r != buf[0])
+ return got_ferror(o->f, GOT_ERR_IO);
+ err = append(&m->delta_buf, &len, &delta_size,
+ content, buf[0]);
+ if (err)
+ return err;
+ n += buf[0];
+ }
+ }
+ }
+
+ m->delta_len = len;
+ return NULL;
+}
+
+static const struct got_error *
encode_delta(struct got_pack_meta *m, struct got_raw_object *o,
struct got_delta_instruction *deltas, int ndeltas,
off_t base_size, FILE *f)
@@ -262,6 +395,7 @@ encode_delta(struct got_pack_meta *m, struct got_raw_object *o,
}
}
+ m->delta_len = ftello(f) - m->delta_offset;
return NULL;
}
@@ -294,7 +428,8 @@ pick_deltas(struct got_pack_meta **meta, int nmeta, int nours,
struct got_pack_meta *m = NULL, *base = NULL;
struct got_raw_object *raw = NULL, *base_raw = NULL;
struct got_delta_instruction *deltas = NULL, *best_deltas = NULL;
- int i, j, size, best_size, ndeltas, best_ndeltas;
+ int i, j, ndeltas, best_ndeltas;
+ off_t size, best_size;
const int max_base_candidates = 3;
int outfd = -1;
@@ -412,15 +547,19 @@ pick_deltas(struct got_pack_meta **meta, int nmeta, int nours,
}
if (best_ndeltas > 0) {
- m->delta_offset = ftello(delta_cache);
- err = encode_delta(m, raw, best_deltas,
- best_ndeltas, m->prev->size, delta_cache);
+ if (best_size <= GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
+ err = encode_delta_in_mem(m, raw, best_deltas,
+ best_ndeltas, best_size, m->prev->size);
+ } else {
+ m->delta_offset = ftello(delta_cache);
+ err = encode_delta(m, raw, best_deltas,
+ best_ndeltas, m->prev->size, delta_cache);
+ }
free(best_deltas);
best_deltas = NULL;
best_ndeltas = 0;
if (err)
goto done;
- m->delta_len = ftello(delta_cache) - m->delta_offset;
}
got_object_raw_close(raw);
@@ -1193,6 +1332,43 @@ packoff(char *hdr, off_t off)
}
static const struct got_error *
+deltahdr(off_t *packfile_size, SHA1_CTX *ctx, FILE *packfile,
+ struct got_pack_meta *m, int use_offset_deltas)
+{
+ const struct got_error *err;
+ char buf[32];
+ int nh;
+
+ if (use_offset_deltas && m->prev->off != 0) {
+ err = packhdr(&nh, buf, sizeof(buf),
+ GOT_OBJ_TYPE_OFFSET_DELTA, m->delta_len);
+ if (err)
+ return err;
+ nh += packoff(buf + nh, m->off - m->prev->off);
+ err = hwrite(packfile, buf, nh, ctx);
+ if (err)
+ return err;
+ *packfile_size += nh;
+ } else {
+ err = packhdr(&nh, buf, sizeof(buf),
+ GOT_OBJ_TYPE_REF_DELTA, m->delta_len);
+ if (err)
+ return err;
+ err = hwrite(packfile, buf, nh, ctx);
+ if (err)
+ return err;
+ *packfile_size += nh;
+ err = hwrite(packfile, m->prev->id.sha1,
+ sizeof(m->prev->id.sha1), ctx);
+ if (err)
+ return err;
+ *packfile_size += sizeof(m->prev->id.sha1);
+ }
+
+ return NULL;
+}
+
+static const struct got_error *
genpack(uint8_t *pack_sha1, FILE *packfile, FILE *delta_cache,
struct got_pack_meta **meta, int nmeta, int nours,
int use_offset_deltas, struct got_repository *repo,
@@ -1267,6 +1443,18 @@ genpack(uint8_t *pack_sha1, FILE *packfile, FILE *delta_cache,
packfile_size += outlen;
got_object_raw_close(raw);
raw = NULL;
+ } else if (m->delta_buf) {
+ err = deltahdr(&packfile_size, &ctx, packfile,
+ m, use_offset_deltas);
+ if (err)
+ goto done;
+ err = got_deflate_to_file_mmap(&outlen,
+ m->delta_buf, 0, m->delta_len, packfile, &csum);
+ if (err)
+ goto done;
+ packfile_size += outlen;
+ free(m->delta_buf);
+ m->delta_buf = NULL;
} else {
off_t remain;
if (delta_file == NULL) {
@@ -1309,30 +1497,10 @@ genpack(uint8_t *pack_sha1, FILE *packfile, FILE *delta_cache,
}
remain -= n;
}
- if (use_offset_deltas && m->prev->off != 0) {
- err = packhdr(&nh, buf, sizeof(buf),
- GOT_OBJ_TYPE_OFFSET_DELTA, m->delta_len);
- if (err)
- goto done;
- nh += packoff(buf + nh,
- m->off - m->prev->off);
- err = hwrite(packfile, buf, nh, &ctx);
- if (err)
- goto done;
- packfile_size += nh;
- } else {
- err = packhdr(&nh, buf, sizeof(buf),
- GOT_OBJ_TYPE_REF_DELTA, m->delta_len);
- err = hwrite(packfile, buf, nh, &ctx);
- if (err)
- goto done;
- packfile_size += nh;
- err = hwrite(packfile, m->prev->id.sha1,
- sizeof(m->prev->id.sha1), &ctx);
- packfile_size += sizeof(m->prev->id.sha1);
- if (err)
- goto done;
- }
+ err = deltahdr(&packfile_size, &ctx, packfile,
+ m, use_offset_deltas);
+ if (err)
+ goto done;
if (fseeko(delta_file, 0L, SEEK_SET) == -1) {
err = got_error_from_errno("fseeko");
goto done;