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reftable: (de)serialization for the polymorphic record type. 

The reftable format is structured as a sequence of blocks, and each block
contains a sequence of prefix-compressed key-value records. There are 4 types of
records, and they have similarities in how they must be handled. This is
achieved by introducing a polymorphic 'record' type that encapsulates ref, log,
index and object records.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Han-Wen Nienhuys 2021-10-07 20:25:02 +00:00 committed by Junio C Hamano
parent 1214aa841b
commit e303bf22f9
7 changed files with 1901 additions and 1 deletions
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2
Makefile
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@ -2453,7 +2453,9 @@ REFTABLE_OBJS += reftable/basics.o
REFTABLE_OBJS += reftable/error.o
REFTABLE_OBJS += reftable/blocksource.o
REFTABLE_OBJS += reftable/publicbasics.o
REFTABLE_OBJS += reftable/record.o
REFTABLE_TEST_OBJS += reftable/record_test.o
REFTABLE_TEST_OBJS += reftable/test_framework.o
REFTABLE_TEST_OBJS += reftable/basics_test.o

21
reftable/constants.h Normal file
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@ -0,0 +1,21 @@
/*
Copyright 2020 Google LLC
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file or at
https://developers.google.com/open-source/licenses/bsd
*/
#ifndef CONSTANTS_H
#define CONSTANTS_H
#define BLOCK_TYPE_LOG 'g'
#define BLOCK_TYPE_INDEX 'i'
#define BLOCK_TYPE_REF 'r'
#define BLOCK_TYPE_OBJ 'o'
#define BLOCK_TYPE_ANY 0
#define MAX_RESTARTS ((1 << 16) - 1)
#define DEFAULT_BLOCK_SIZE 4096
#endif

1212
reftable/record.c Normal file
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@ -0,0 +1,1212 @@
/*
Copyright 2020 Google LLC
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file or at
https://developers.google.com/open-source/licenses/bsd
*/
/* record.c - methods for different types of records. */
#include "record.h"
#include "system.h"
#include "constants.h"
#include "reftable-error.h"
#include "basics.h"
int get_var_int(uint64_t *dest, struct string_view *in)
{
int ptr = 0;
uint64_t val;
if (in->len == 0)
return -1;
val = in->buf[ptr] & 0x7f;
while (in->buf[ptr] & 0x80) {
ptr++;
if (ptr > in->len) {
return -1;
}
val = (val + 1) << 7 | (uint64_t)(in->buf[ptr] & 0x7f);
}
*dest = val;
return ptr + 1;
}
int put_var_int(struct string_view *dest, uint64_t val)
{
uint8_t buf[10] = { 0 };
int i = 9;
int n = 0;
buf[i] = (uint8_t)(val & 0x7f);
i--;
while (1) {
val >>= 7;
if (!val) {
break;
}
val--;
buf[i] = 0x80 | (uint8_t)(val & 0x7f);
i--;
}
n = sizeof(buf) - i - 1;
if (dest->len < n)
return -1;
memcpy(dest->buf, &buf[i + 1], n);
return n;
}
int reftable_is_block_type(uint8_t typ)
{
switch (typ) {
case BLOCK_TYPE_REF:
case BLOCK_TYPE_LOG:
case BLOCK_TYPE_OBJ:
case BLOCK_TYPE_INDEX:
return 1;
}
return 0;
}
uint8_t *reftable_ref_record_val1(struct reftable_ref_record *rec)
{
switch (rec->value_type) {
case REFTABLE_REF_VAL1:
return rec->value.val1;
case REFTABLE_REF_VAL2:
return rec->value.val2.value;
default:
return NULL;
}
}
uint8_t *reftable_ref_record_val2(struct reftable_ref_record *rec)
{
switch (rec->value_type) {
case REFTABLE_REF_VAL2:
return rec->value.val2.target_value;
default:
return NULL;
}
}
static int decode_string(struct strbuf *dest, struct string_view in)
{
int start_len = in.len;
uint64_t tsize = 0;
int n = get_var_int(&tsize, &in);
if (n <= 0)
return -1;
string_view_consume(&in, n);
if (in.len < tsize)
return -1;
strbuf_reset(dest);
strbuf_add(dest, in.buf, tsize);
string_view_consume(&in, tsize);
return start_len - in.len;
}
static int encode_string(char *str, struct string_view s)
{
struct string_view start = s;
int l = strlen(str);
int n = put_var_int(&s, l);
if (n < 0)
return -1;
string_view_consume(&s, n);
if (s.len < l)
return -1;
memcpy(s.buf, str, l);
string_view_consume(&s, l);
return start.len - s.len;
}
int reftable_encode_key(int *restart, struct string_view dest,
struct strbuf prev_key, struct strbuf key,
uint8_t extra)
{
struct string_view start = dest;
int prefix_len = common_prefix_size(&prev_key, &key);
uint64_t suffix_len = key.len - prefix_len;
int n = put_var_int(&dest, (uint64_t)prefix_len);
if (n < 0)
return -1;
string_view_consume(&dest, n);
*restart = (prefix_len == 0);
n = put_var_int(&dest, suffix_len << 3 | (uint64_t)extra);
if (n < 0)
return -1;
string_view_consume(&dest, n);
if (dest.len < suffix_len)
return -1;
memcpy(dest.buf, key.buf + prefix_len, suffix_len);
string_view_consume(&dest, suffix_len);
return start.len - dest.len;
}
int reftable_decode_key(struct strbuf *key, uint8_t *extra,
struct strbuf last_key, struct string_view in)
{
int start_len = in.len;
uint64_t prefix_len = 0;
uint64_t suffix_len = 0;
int n = get_var_int(&prefix_len, &in);
if (n < 0)
return -1;
string_view_consume(&in, n);
if (prefix_len > last_key.len)
return -1;
n = get_var_int(&suffix_len, &in);
if (n <= 0)
return -1;
string_view_consume(&in, n);
*extra = (uint8_t)(suffix_len & 0x7);
suffix_len >>= 3;
if (in.len < suffix_len)
return -1;
strbuf_reset(key);
strbuf_add(key, last_key.buf, prefix_len);
strbuf_add(key, in.buf, suffix_len);
string_view_consume(&in, suffix_len);
return start_len - in.len;
}
static void reftable_ref_record_key(const void *r, struct strbuf *dest)
{
const struct reftable_ref_record *rec =
(const struct reftable_ref_record *)r;
strbuf_reset(dest);
strbuf_addstr(dest, rec->refname);
}
static void reftable_ref_record_copy_from(void *rec, const void *src_rec,
int hash_size)
{
struct reftable_ref_record *ref = rec;
const struct reftable_ref_record *src = src_rec;
assert(hash_size > 0);
/* This is simple and correct, but we could probably reuse the hash
* fields. */
reftable_ref_record_release(ref);
if (src->refname) {
ref->refname = xstrdup(src->refname);
}
ref->update_index = src->update_index;
ref->value_type = src->value_type;
switch (src->value_type) {
case REFTABLE_REF_DELETION:
break;
case REFTABLE_REF_VAL1:
ref->value.val1 = reftable_malloc(hash_size);
memcpy(ref->value.val1, src->value.val1, hash_size);
break;
case REFTABLE_REF_VAL2:
ref->value.val2.value = reftable_malloc(hash_size);
memcpy(ref->value.val2.value, src->value.val2.value, hash_size);
ref->value.val2.target_value = reftable_malloc(hash_size);
memcpy(ref->value.val2.target_value,
src->value.val2.target_value, hash_size);
break;
case REFTABLE_REF_SYMREF:
ref->value.symref = xstrdup(src->value.symref);
break;
}
}
static char hexdigit(int c)
{
if (c <= 9)
return '0' + c;
return 'a' + (c - 10);
}
static void hex_format(char *dest, uint8_t *src, int hash_size)
{
assert(hash_size > 0);
if (src) {
int i = 0;
for (i = 0; i < hash_size; i++) {
dest[2 * i] = hexdigit(src[i] >> 4);
dest[2 * i + 1] = hexdigit(src[i] & 0xf);
}
dest[2 * hash_size] = 0;
}
}
void reftable_ref_record_print(struct reftable_ref_record *ref,
uint32_t hash_id)
{
char hex[2 * GIT_SHA256_RAWSZ + 1] = { 0 }; /* BUG */
printf("ref{%s(%" PRIu64 ") ", ref->refname, ref->update_index);
switch (ref->value_type) {
case REFTABLE_REF_SYMREF:
printf("=> %s", ref->value.symref);
break;
case REFTABLE_REF_VAL2:
hex_format(hex, ref->value.val2.value, hash_size(hash_id));
printf("val 2 %s", hex);
hex_format(hex, ref->value.val2.target_value,
hash_size(hash_id));
printf("(T %s)", hex);
break;
case REFTABLE_REF_VAL1:
hex_format(hex, ref->value.val1, hash_size(hash_id));
printf("val 1 %s", hex);
break;
case REFTABLE_REF_DELETION:
printf("delete");
break;
}
printf("}\n");
}
static void reftable_ref_record_release_void(void *rec)
{
reftable_ref_record_release(rec);
}
void reftable_ref_record_release(struct reftable_ref_record *ref)
{
switch (ref->value_type) {
case REFTABLE_REF_SYMREF:
reftable_free(ref->value.symref);
break;
case REFTABLE_REF_VAL2:
reftable_free(ref->value.val2.target_value);
reftable_free(ref->value.val2.value);
break;
case REFTABLE_REF_VAL1:
reftable_free(ref->value.val1);
break;
case REFTABLE_REF_DELETION:
break;
default:
abort();
}
reftable_free(ref->refname);
memset(ref, 0, sizeof(struct reftable_ref_record));
}
static uint8_t reftable_ref_record_val_type(const void *rec)
{
const struct reftable_ref_record *r =
(const struct reftable_ref_record *)rec;
return r->value_type;
}
static int reftable_ref_record_encode(const void *rec, struct string_view s,
int hash_size)
{
const struct reftable_ref_record *r =
(const struct reftable_ref_record *)rec;
struct string_view start = s;
int n = put_var_int(&s, r->update_index);
assert(hash_size > 0);
if (n < 0)
return -1;
string_view_consume(&s, n);
switch (r->value_type) {
case REFTABLE_REF_SYMREF:
n = encode_string(r->value.symref, s);
if (n < 0) {
return -1;
}
string_view_consume(&s, n);
break;
case REFTABLE_REF_VAL2:
if (s.len < 2 * hash_size) {
return -1;
}
memcpy(s.buf, r->value.val2.value, hash_size);
string_view_consume(&s, hash_size);
memcpy(s.buf, r->value.val2.target_value, hash_size);
string_view_consume(&s, hash_size);
break;
case REFTABLE_REF_VAL1:
if (s.len < hash_size) {
return -1;
}
memcpy(s.buf, r->value.val1, hash_size);
string_view_consume(&s, hash_size);
break;
case REFTABLE_REF_DELETION:
break;
default:
abort();
}
return start.len - s.len;
}
static int reftable_ref_record_decode(void *rec, struct strbuf key,
uint8_t val_type, struct string_view in,
int hash_size)
{
struct reftable_ref_record *r = rec;
struct string_view start = in;
uint64_t update_index = 0;
int n = get_var_int(&update_index, &in);
if (n < 0)
return n;
string_view_consume(&in, n);
reftable_ref_record_release(r);
assert(hash_size > 0);
r->refname = reftable_realloc(r->refname, key.len + 1);
memcpy(r->refname, key.buf, key.len);
r->update_index = update_index;
r->refname[key.len] = 0;
r->value_type = val_type;
switch (val_type) {
case REFTABLE_REF_VAL1:
if (in.len < hash_size) {
return -1;
}
r->value.val1 = reftable_malloc(hash_size);
memcpy(r->value.val1, in.buf, hash_size);
string_view_consume(&in, hash_size);
break;
case REFTABLE_REF_VAL2:
if (in.len < 2 * hash_size) {
return -1;
}
r->value.val2.value = reftable_malloc(hash_size);
memcpy(r->value.val2.value, in.buf, hash_size);
string_view_consume(&in, hash_size);
r->value.val2.target_value = reftable_malloc(hash_size);
memcpy(r->value.val2.target_value, in.buf, hash_size);
string_view_consume(&in, hash_size);
break;
case REFTABLE_REF_SYMREF: {
struct strbuf dest = STRBUF_INIT;
int n = decode_string(&dest, in);
if (n < 0) {
return -1;
}
string_view_consume(&in, n);
r->value.symref = dest.buf;
} break;
case REFTABLE_REF_DELETION:
break;
default:
abort();
break;
}
return start.len - in.len;
}
static int reftable_ref_record_is_deletion_void(const void *p)
{
return reftable_ref_record_is_deletion(
(const struct reftable_ref_record *)p);
}
static struct reftable_record_vtable reftable_ref_record_vtable = {
.key = &reftable_ref_record_key,
.type = BLOCK_TYPE_REF,
.copy_from = &reftable_ref_record_copy_from,
.val_type = &reftable_ref_record_val_type,
.encode = &reftable_ref_record_encode,
.decode = &reftable_ref_record_decode,
.release = &reftable_ref_record_release_void,
.is_deletion = &reftable_ref_record_is_deletion_void,
};
static void reftable_obj_record_key(const void *r, struct strbuf *dest)
{
const struct reftable_obj_record *rec =
(const struct reftable_obj_record *)r;
strbuf_reset(dest);
strbuf_add(dest, rec->hash_prefix, rec->hash_prefix_len);
}
static void reftable_obj_record_release(void *rec)
{
struct reftable_obj_record *obj = rec;
FREE_AND_NULL(obj->hash_prefix);
FREE_AND_NULL(obj->offsets);
memset(obj, 0, sizeof(struct reftable_obj_record));
}
static void reftable_obj_record_copy_from(void *rec, const void *src_rec,
int hash_size)
{
struct reftable_obj_record *obj = rec;
const struct reftable_obj_record *src =
(const struct reftable_obj_record *)src_rec;
reftable_obj_record_release(obj);
*obj = *src;
obj->hash_prefix = reftable_malloc(obj->hash_prefix_len);
memcpy(obj->hash_prefix, src->hash_prefix, obj->hash_prefix_len);
obj->offsets = reftable_malloc(obj->offset_len * sizeof(uint64_t));
COPY_ARRAY(obj->offsets, src->offsets, obj->offset_len);
}
static uint8_t reftable_obj_record_val_type(const void *rec)
{
const struct reftable_obj_record *r = rec;
if (r->offset_len > 0 && r->offset_len < 8)
return r->offset_len;
return 0;
}
static int reftable_obj_record_encode(const void *rec, struct string_view s,
int hash_size)
{
const struct reftable_obj_record *r = rec;
struct string_view start = s;
int i = 0;
int n = 0;
uint64_t last = 0;
if (r->offset_len == 0 || r->offset_len >= 8) {
n = put_var_int(&s, r->offset_len);
if (n < 0) {
return -1;
}
string_view_consume(&s, n);
}
if (r->offset_len == 0)
return start.len - s.len;
n = put_var_int(&s, r->offsets[0]);
if (n < 0)
return -1;
string_view_consume(&s, n);
last = r->offsets[0];
for (i = 1; i < r->offset_len; i++) {
int n = put_var_int(&s, r->offsets[i] - last);
if (n < 0) {
return -1;
}
string_view_consume(&s, n);
last = r->offsets[i];
}
return start.len - s.len;
}
static int reftable_obj_record_decode(void *rec, struct strbuf key,
uint8_t val_type, struct string_view in,
int hash_size)
{
struct string_view start = in;
struct reftable_obj_record *r = rec;
uint64_t count = val_type;
int n = 0;
uint64_t last;
int j;
r->hash_prefix = reftable_malloc(key.len);
memcpy(r->hash_prefix, key.buf, key.len);
r->hash_prefix_len = key.len;
if (val_type == 0) {
n = get_var_int(&count, &in);
if (n < 0) {
return n;
}
string_view_consume(&in, n);
}
r->offsets = NULL;
r->offset_len = 0;
if (count == 0)
return start.len - in.len;
r->offsets = reftable_malloc(count * sizeof(uint64_t));
r->offset_len = count;
n = get_var_int(&r->offsets[0], &in);
if (n < 0)
return n;
string_view_consume(&in, n);
last = r->offsets[0];
j = 1;
while (j < count) {
uint64_t delta = 0;
int n = get_var_int(&delta, &in);
if (n < 0) {
return n;
}
string_view_consume(&in, n);
last = r->offsets[j] = (delta + last);
j++;
}
return start.len - in.len;
}
static int not_a_deletion(const void *p)
{
return 0;
}
static struct reftable_record_vtable reftable_obj_record_vtable = {
.key = &reftable_obj_record_key,
.type = BLOCK_TYPE_OBJ,
.copy_from = &reftable_obj_record_copy_from,
.val_type = &reftable_obj_record_val_type,
.encode = &reftable_obj_record_encode,
.decode = &reftable_obj_record_decode,
.release = &reftable_obj_record_release,
.is_deletion = not_a_deletion,
};
void reftable_log_record_print(struct reftable_log_record *log,
uint32_t hash_id)
{
char hex[GIT_SHA256_RAWSZ + 1] = { 0 };
switch (log->value_type) {
case REFTABLE_LOG_DELETION:
printf("log{%s(%" PRIu64 ") delete", log->refname,
log->update_index);
break;
case REFTABLE_LOG_UPDATE:
printf("log{%s(%" PRIu64 ") %s <%s> %" PRIu64 " %04d\n",
log->refname, log->update_index, log->value.update.name,
log->value.update.email, log->value.update.time,
log->value.update.tz_offset);
hex_format(hex, log->value.update.old_hash, hash_size(hash_id));
printf("%s => ", hex);
hex_format(hex, log->value.update.new_hash, hash_size(hash_id));
printf("%s\n\n%s\n}\n", hex, log->value.update.message);
break;
}
}
static void reftable_log_record_key(const void *r, struct strbuf *dest)
{
const struct reftable_log_record *rec =
(const struct reftable_log_record *)r;
int len = strlen(rec->refname);
uint8_t i64[8];
uint64_t ts = 0;
strbuf_reset(dest);
strbuf_add(dest, (uint8_t *)rec->refname, len + 1);
ts = (~ts) - rec->update_index;
put_be64(&i64[0], ts);
strbuf_add(dest, i64, sizeof(i64));
}
static void reftable_log_record_copy_from(void *rec, const void *src_rec,
int hash_size)
{
struct reftable_log_record *dst = rec;
const struct reftable_log_record *src =
(const struct reftable_log_record *)src_rec;
reftable_log_record_release(dst);
*dst = *src;
if (dst->refname) {
dst->refname = xstrdup(dst->refname);
}
switch (dst->value_type) {
case REFTABLE_LOG_DELETION:
break;
case REFTABLE_LOG_UPDATE:
if (dst->value.update.email) {
dst->value.update.email =
xstrdup(dst->value.update.email);
}
if (dst->value.update.name) {
dst->value.update.name =
xstrdup(dst->value.update.name);
}
if (dst->value.update.message) {
dst->value.update.message =
xstrdup(dst->value.update.message);
}
if (dst->value.update.new_hash) {
dst->value.update.new_hash = reftable_malloc(hash_size);
memcpy(dst->value.update.new_hash,
src->value.update.new_hash, hash_size);
}
if (dst->value.update.old_hash) {
dst->value.update.old_hash = reftable_malloc(hash_size);
memcpy(dst->value.update.old_hash,
src->value.update.old_hash, hash_size);
}
break;
}
}
static void reftable_log_record_release_void(void *rec)
{
struct reftable_log_record *r = rec;
reftable_log_record_release(r);
}
void reftable_log_record_release(struct reftable_log_record *r)
{
reftable_free(r->refname);
switch (r->value_type) {
case REFTABLE_LOG_DELETION:
break;
case REFTABLE_LOG_UPDATE:
reftable_free(r->value.update.new_hash);
reftable_free(r->value.update.old_hash);
reftable_free(r->value.update.name);
reftable_free(r->value.update.email);
reftable_free(r->value.update.message);
break;
}
memset(r, 0, sizeof(struct reftable_log_record));
}
static uint8_t reftable_log_record_val_type(const void *rec)
{
const struct reftable_log_record *log =
(const struct reftable_log_record *)rec;
return reftable_log_record_is_deletion(log) ? 0 : 1;
}
static uint8_t zero[GIT_SHA256_RAWSZ] = { 0 };
static int reftable_log_record_encode(const void *rec, struct string_view s,
int hash_size)
{
const struct reftable_log_record *r = rec;
struct string_view start = s;
int n = 0;
uint8_t *oldh = NULL;
uint8_t *newh = NULL;
if (reftable_log_record_is_deletion(r))
return 0;
oldh = r->value.update.old_hash;
newh = r->value.update.new_hash;
if (!oldh) {
oldh = zero;
}
if (!newh) {
newh = zero;
}
if (s.len < 2 * hash_size)
return -1;
memcpy(s.buf, oldh, hash_size);
memcpy(s.buf + hash_size, newh, hash_size);
string_view_consume(&s, 2 * hash_size);
n = encode_string(r->value.update.name ? r->value.update.name : "", s);
if (n < 0)
return -1;
string_view_consume(&s, n);
n = encode_string(r->value.update.email ? r->value.update.email : "",
s);
if (n < 0)
return -1;
string_view_consume(&s, n);
n = put_var_int(&s, r->value.update.time);
if (n < 0)
return -1;
string_view_consume(&s, n);
if (s.len < 2)
return -1;
put_be16(s.buf, r->value.update.tz_offset);
string_view_consume(&s, 2);
n = encode_string(
r->value.update.message ? r->value.update.message : "", s);
if (n < 0)
return -1;
string_view_consume(&s, n);
return start.len - s.len;
}
static int reftable_log_record_decode(void *rec, struct strbuf key,
uint8_t val_type, struct string_view in,
int hash_size)
{
struct string_view start = in;
struct reftable_log_record *r = rec;
uint64_t max = 0;
uint64_t ts = 0;
struct strbuf dest = STRBUF_INIT;
int n;
if (key.len <= 9 || key.buf[key.len - 9] != 0)
return REFTABLE_FORMAT_ERROR;
r->refname = reftable_realloc(r->refname, key.len - 8);
memcpy(r->refname, key.buf, key.len - 8);
ts = get_be64(key.buf + key.len - 8);
r->update_index = (~max) - ts;
if (val_type != r->value_type) {
switch (r->value_type) {
case REFTABLE_LOG_UPDATE:
FREE_AND_NULL(r->value.update.old_hash);
FREE_AND_NULL(r->value.update.new_hash);
FREE_AND_NULL(r->value.update.message);
FREE_AND_NULL(r->value.update.email);
FREE_AND_NULL(r->value.update.name);
break;
case REFTABLE_LOG_DELETION:
break;
}
}
r->value_type = val_type;
if (val_type == REFTABLE_LOG_DELETION)
return 0;
if (in.len < 2 * hash_size)
return REFTABLE_FORMAT_ERROR;
r->value.update.old_hash =
reftable_realloc(r->value.update.old_hash, hash_size);
r->value.update.new_hash =
reftable_realloc(r->value.update.new_hash, hash_size);
memcpy(r->value.update.old_hash, in.buf, hash_size);
memcpy(r->value.update.new_hash, in.buf + hash_size, hash_size);
string_view_consume(&in, 2 * hash_size);
n = decode_string(&dest, in);
if (n < 0)
goto done;
string_view_consume(&in, n);
r->value.update.name =
reftable_realloc(r->value.update.name, dest.len + 1);
memcpy(r->value.update.name, dest.buf, dest.len);
r->value.update.name[dest.len] = 0;
strbuf_reset(&dest);
n = decode_string(&dest, in);
if (n < 0)
goto done;
string_view_consume(&in, n);
r->value.update.email =
reftable_realloc(r->value.update.email, dest.len + 1);
memcpy(r->value.update.email, dest.buf, dest.len);
r->value.update.email[dest.len] = 0;
ts = 0;
n = get_var_int(&ts, &in);
if (n < 0)
goto done;
string_view_consume(&in, n);
r->value.update.time = ts;
if (in.len < 2)
goto done;
r->value.update.tz_offset = get_be16(in.buf);
string_view_consume(&in, 2);
strbuf_reset(&dest);
n = decode_string(&dest, in);
if (n < 0)
goto done;
string_view_consume(&in, n);
r->value.update.message =
reftable_realloc(r->value.update.message, dest.len + 1);
memcpy(r->value.update.message, dest.buf, dest.len);
r->value.update.message[dest.len] = 0;
strbuf_release(&dest);
return start.len - in.len;
done:
strbuf_release(&dest);
return REFTABLE_FORMAT_ERROR;
}
static int null_streq(char *a, char *b)
{
char *empty = "";
if (!a)
a = empty;
if (!b)
b = empty;
return 0 == strcmp(a, b);
}
static int zero_hash_eq(uint8_t *a, uint8_t *b, int sz)
{
if (!a)
a = zero;
if (!b)
b = zero;
return !memcmp(a, b, sz);
}
int reftable_log_record_equal(struct reftable_log_record *a,
struct reftable_log_record *b, int hash_size)
{
if (!(null_streq(a->refname, b->refname) &&
a->update_index == b->update_index &&
a->value_type == b->value_type))
return 0;
switch (a->value_type) {
case REFTABLE_LOG_DELETION:
return 1;
case REFTABLE_LOG_UPDATE:
return null_streq(a->value.update.name, b->value.update.name) &&
a->value.update.time == b->value.update.time &&
a->value.update.tz_offset == b->value.update.tz_offset &&
null_streq(a->value.update.email,
b->value.update.email) &&
null_streq(a->value.update.message,
b->value.update.message) &&
zero_hash_eq(a->value.update.old_hash,
b->value.update.old_hash, hash_size) &&
zero_hash_eq(a->value.update.new_hash,
b->value.update.new_hash, hash_size);
}
abort();
}
static int reftable_log_record_is_deletion_void(const void *p)
{
return reftable_log_record_is_deletion(
(const struct reftable_log_record *)p);
}
static struct reftable_record_vtable reftable_log_record_vtable = {
.key = &reftable_log_record_key,
.type = BLOCK_TYPE_LOG,
.copy_from = &reftable_log_record_copy_from,
.val_type = &reftable_log_record_val_type,
.encode = &reftable_log_record_encode,
.decode = &reftable_log_record_decode,
.release = &reftable_log_record_release_void,
.is_deletion = &reftable_log_record_is_deletion_void,
};
struct reftable_record reftable_new_record(uint8_t typ)
{
struct reftable_record rec = { NULL };
switch (typ) {
case BLOCK_TYPE_REF: {
struct reftable_ref_record *r =
reftable_calloc(sizeof(struct reftable_ref_record));
reftable_record_from_ref(&rec, r);
return rec;
}
case BLOCK_TYPE_OBJ: {
struct reftable_obj_record *r =
reftable_calloc(sizeof(struct reftable_obj_record));
reftable_record_from_obj(&rec, r);
return rec;
}
case BLOCK_TYPE_LOG: {
struct reftable_log_record *r =
reftable_calloc(sizeof(struct reftable_log_record));
reftable_record_from_log(&rec, r);
return rec;
}
case BLOCK_TYPE_INDEX: {
struct reftable_index_record empty = { .last_key =
STRBUF_INIT };
struct reftable_index_record *r =
reftable_calloc(sizeof(struct reftable_index_record));
*r = empty;
reftable_record_from_index(&rec, r);
return rec;
}
}
abort();
return rec;
}
/* clear out the record, yielding the reftable_record data that was
* encapsulated. */
static void *reftable_record_yield(struct reftable_record *rec)
{
void *p = rec->data;
rec->data = NULL;
return p;
}
void reftable_record_destroy(struct reftable_record *rec)
{
reftable_record_release(rec);
reftable_free(reftable_record_yield(rec));
}
static void reftable_index_record_key(const void *r, struct strbuf *dest)
{
const struct reftable_index_record *rec = r;
strbuf_reset(dest);
strbuf_addbuf(dest, &rec->last_key);
}
static void reftable_index_record_copy_from(void *rec, const void *src_rec,
int hash_size)
{
struct reftable_index_record *dst = rec;
const struct reftable_index_record *src = src_rec;
strbuf_reset(&dst->last_key);
strbuf_addbuf(&dst->last_key, &src->last_key);
dst->offset = src->offset;
}
static void reftable_index_record_release(void *rec)
{
struct reftable_index_record *idx = rec;
strbuf_release(&idx->last_key);
}
static uint8_t reftable_index_record_val_type(const void *rec)
{
return 0;
}
static int reftable_index_record_encode(const void *rec, struct string_view out,
int hash_size)
{
const struct reftable_index_record *r =
(const struct reftable_index_record *)rec;
struct string_view start = out;
int n = put_var_int(&out, r->offset);
if (n < 0)
return n;
string_view_consume(&out, n);
return start.len - out.len;
}
static int reftable_index_record_decode(void *rec, struct strbuf key,
uint8_t val_type, struct string_view in,
int hash_size)
{
struct string_view start = in;
struct reftable_index_record *r = rec;
int n = 0;
strbuf_reset(&r->last_key);
strbuf_addbuf(&r->last_key, &key);
n = get_var_int(&r->offset, &in);
if (n < 0)
return n;
string_view_consume(&in, n);
return start.len - in.len;
}
static struct reftable_record_vtable reftable_index_record_vtable = {
.key = &reftable_index_record_key,
.type = BLOCK_TYPE_INDEX,
.copy_from = &reftable_index_record_copy_from,
.val_type = &reftable_index_record_val_type,
.encode = &reftable_index_record_encode,
.decode = &reftable_index_record_decode,
.release = &reftable_index_record_release,
.is_deletion = &not_a_deletion,
};
void reftable_record_key(struct reftable_record *rec, struct strbuf *dest)
{
rec->ops->key(rec->data, dest);
}
uint8_t reftable_record_type(struct reftable_record *rec)
{
return rec->ops->type;
}
int reftable_record_encode(struct reftable_record *rec, struct string_view dest,
int hash_size)
{
return rec->ops->encode(rec->data, dest, hash_size);
}
void reftable_record_copy_from(struct reftable_record *rec,
struct reftable_record *src, int hash_size)
{
assert(src->ops->type == rec->ops->type);
rec->ops->copy_from(rec->data, src->data, hash_size);
}
uint8_t reftable_record_val_type(struct reftable_record *rec)
{
return rec->ops->val_type(rec->data);
}
int reftable_record_decode(struct reftable_record *rec, struct strbuf key,
uint8_t extra, struct string_view src, int hash_size)
{
return rec->ops->decode(rec->data, key, extra, src, hash_size);
}
void reftable_record_release(struct reftable_record *rec)
{
rec->ops->release(rec->data);
}
int reftable_record_is_deletion(struct reftable_record *rec)
{
return rec->ops->is_deletion(rec->data);
}
void reftable_record_from_ref(struct reftable_record *rec,
struct reftable_ref_record *ref_rec)
{
assert(!rec->ops);
rec->data = ref_rec;
rec->ops = &reftable_ref_record_vtable;
}
void reftable_record_from_obj(struct reftable_record *rec,
struct reftable_obj_record *obj_rec)
{
assert(!rec->ops);
rec->data = obj_rec;
rec->ops = &reftable_obj_record_vtable;
}
void reftable_record_from_index(struct reftable_record *rec,
struct reftable_index_record *index_rec)
{
assert(!rec->ops);
rec->data = index_rec;
rec->ops = &reftable_index_record_vtable;
}
void reftable_record_from_log(struct reftable_record *rec,
struct reftable_log_record *log_rec)
{
assert(!rec->ops);
rec->data = log_rec;
rec->ops = &reftable_log_record_vtable;
}
struct reftable_ref_record *reftable_record_as_ref(struct reftable_record *rec)
{
assert(reftable_record_type(rec) == BLOCK_TYPE_REF);
return rec->data;
}
struct reftable_log_record *reftable_record_as_log(struct reftable_record *rec)
{
assert(reftable_record_type(rec) == BLOCK_TYPE_LOG);
return rec->data;
}
static int hash_equal(uint8_t *a, uint8_t *b, int hash_size)
{
if (a && b)
return !memcmp(a, b, hash_size);
return a == b;
}
int reftable_ref_record_equal(struct reftable_ref_record *a,
struct reftable_ref_record *b, int hash_size)
{
assert(hash_size > 0);
if (!(0 == strcmp(a->refname, b->refname) &&
a->update_index == b->update_index &&
a->value_type == b->value_type))
return 0;
switch (a->value_type) {
case REFTABLE_REF_SYMREF:
return !strcmp(a->value.symref, b->value.symref);
case REFTABLE_REF_VAL2:
return hash_equal(a->value.val2.value, b->value.val2.value,
hash_size) &&
hash_equal(a->value.val2.target_value,
b->value.val2.target_value, hash_size);
case REFTABLE_REF_VAL1:
return hash_equal(a->value.val1, b->value.val1, hash_size);
case REFTABLE_REF_DELETION:
return 1;
default:
abort();
}
}
int reftable_ref_record_compare_name(const void *a, const void *b)
{
return strcmp(((struct reftable_ref_record *)a)->refname,
((struct reftable_ref_record *)b)->refname);
}
int reftable_ref_record_is_deletion(const struct reftable_ref_record *ref)
{
return ref->value_type == REFTABLE_REF_DELETION;
}
int reftable_log_record_compare_key(const void *a, const void *b)
{
const struct reftable_log_record *la = a;
const struct reftable_log_record *lb = b;
int cmp = strcmp(la->refname, lb->refname);
if (cmp)
return cmp;
if (la->update_index > lb->update_index)
return -1;
return (la->update_index < lb->update_index) ? 1 : 0;
}
int reftable_log_record_is_deletion(const struct reftable_log_record *log)
{
return (log->value_type == REFTABLE_LOG_DELETION);
}
void string_view_consume(struct string_view *s, int n)
{
s->buf += n;
s->len -= n;
}

139
reftable/record.h Normal file
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/*
Copyright 2020 Google LLC
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file or at
https://developers.google.com/open-source/licenses/bsd
*/
#ifndef RECORD_H
#define RECORD_H
#include "system.h"
#include <stdint.h>
#include "reftable-record.h"
/*
* A substring of existing string data. This structure takes no responsibility
* for the lifetime of the data it points to.
*/
struct string_view {
uint8_t *buf;
size_t len;
};
/* Advance `s.buf` by `n`, and decrease length. */
void string_view_consume(struct string_view *s, int n);
/* utilities for de/encoding varints */
int get_var_int(uint64_t *dest, struct string_view *in);
int put_var_int(struct string_view *dest, uint64_t val);
/* Methods for records. */
struct reftable_record_vtable {
/* encode the key of to a uint8_t strbuf. */
void (*key)(const void *rec, struct strbuf *dest);
/* The record type of ('r' for ref). */
uint8_t type;
void (*copy_from)(void *dest, const void *src, int hash_size);
/* a value of [0..7], indicating record subvariants (eg. ref vs. symref
* vs ref deletion) */
uint8_t (*val_type)(const void *rec);
/* encodes rec into dest, returning how much space was used. */
int (*encode)(const void *rec, struct string_view dest, int hash_size);
/* decode data from `src` into the record. */
int (*decode)(void *rec, struct strbuf key, uint8_t extra,
struct string_view src, int hash_size);
/* deallocate and null the record. */
void (*release)(void *rec);
/* is this a tombstone? */
int (*is_deletion)(const void *rec);
};
/* record is a generic wrapper for different types of records. */
struct reftable_record {
void *data;
struct reftable_record_vtable *ops;
};
/* returns true for recognized block types. Block start with the block type. */
int reftable_is_block_type(uint8_t typ);
/* creates a malloced record of the given type. Dispose with record_destroy */
struct reftable_record reftable_new_record(uint8_t typ);
/* Encode `key` into `dest`. Sets `is_restart` to indicate a restart. Returns
* number of bytes written. */
int reftable_encode_key(int *is_restart, struct string_view dest,
struct strbuf prev_key, struct strbuf key,
uint8_t extra);
/* Decode into `key` and `extra` from `in` */
int reftable_decode_key(struct strbuf *key, uint8_t *extra,
struct strbuf last_key, struct string_view in);
/* reftable_index_record are used internally to speed up lookups. */
struct reftable_index_record {
uint64_t offset; /* Offset of block */
struct strbuf last_key; /* Last key of the block. */
};
/* reftable_obj_record stores an object ID => ref mapping. */
struct reftable_obj_record {
uint8_t *hash_prefix; /* leading bytes of the object ID */
int hash_prefix_len; /* number of leading bytes. Constant
* across a single table. */
uint64_t *offsets; /* a vector of file offsets. */
int offset_len;
};
/* see struct record_vtable */
void reftable_record_key(struct reftable_record *rec, struct strbuf *dest);
uint8_t reftable_record_type(struct reftable_record *rec);
void reftable_record_copy_from(struct reftable_record *rec,
struct reftable_record *src, int hash_size);
uint8_t reftable_record_val_type(struct reftable_record *rec);
int reftable_record_encode(struct reftable_record *rec, struct string_view dest,
int hash_size);
int reftable_record_decode(struct reftable_record *rec, struct strbuf key,
uint8_t extra, struct string_view src,
int hash_size);
int reftable_record_is_deletion(struct reftable_record *rec);
/* zeroes out the embedded record */
void reftable_record_release(struct reftable_record *rec);
/* clear and deallocate embedded record, and zero `rec`. */
void reftable_record_destroy(struct reftable_record *rec);
/* initialize generic records from concrete records. The generic record should
* be zeroed out. */
void reftable_record_from_obj(struct reftable_record *rec,
struct reftable_obj_record *objrec);
void reftable_record_from_index(struct reftable_record *rec,
struct reftable_index_record *idxrec);
void reftable_record_from_ref(struct reftable_record *rec,
struct reftable_ref_record *refrec);
void reftable_record_from_log(struct reftable_record *rec,
struct reftable_log_record *logrec);
struct reftable_ref_record *reftable_record_as_ref(struct reftable_record *ref);
struct reftable_log_record *reftable_record_as_log(struct reftable_record *ref);
/* for qsort. */
int reftable_ref_record_compare_name(const void *a, const void *b);
/* for qsort. */
int reftable_log_record_compare_key(const void *a, const void *b);
#endif

412
reftable/record_test.c Normal file
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/*
Copyright 2020 Google LLC
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file or at
https://developers.google.com/open-source/licenses/bsd
*/
#include "record.h"
#include "system.h"
#include "basics.h"
#include "constants.h"
#include "test_framework.h"
#include "reftable-tests.h"
static void test_copy(struct reftable_record *rec)
{
struct reftable_record copy =
reftable_new_record(reftable_record_type(rec));
reftable_record_copy_from(&copy, rec, GIT_SHA1_RAWSZ);
/* do it twice to catch memory leaks */
reftable_record_copy_from(&copy, rec, GIT_SHA1_RAWSZ);
switch (reftable_record_type(&copy)) {
case BLOCK_TYPE_REF:
EXPECT(reftable_ref_record_equal(reftable_record_as_ref(&copy),
reftable_record_as_ref(rec),
GIT_SHA1_RAWSZ));
break;
case BLOCK_TYPE_LOG:
EXPECT(reftable_log_record_equal(reftable_record_as_log(&copy),
reftable_record_as_log(rec),
GIT_SHA1_RAWSZ));
break;
}
reftable_record_destroy(&copy);
}
static void test_varint_roundtrip(void)
{
uint64_t inputs[] = { 0,
1,
27,
127,
128,
257,
4096,
((uint64_t)1 << 63),
((uint64_t)1 << 63) + ((uint64_t)1 << 63) - 1 };
int i = 0;
for (i = 0; i < ARRAY_SIZE(inputs); i++) {
uint8_t dest[10];
struct string_view out = {
.buf = dest,
.len = sizeof(dest),
};
uint64_t in = inputs[i];
int n = put_var_int(&out, in);
uint64_t got = 0;
EXPECT(n > 0);
out.len = n;
n = get_var_int(&got, &out);
EXPECT(n > 0);
EXPECT(got == in);
}
}
static void test_common_prefix(void)
{
struct {
const char *a, *b;
int want;
} cases[] = {
{ "abc", "ab", 2 },
{ "", "abc", 0 },
{ "abc", "abd", 2 },
{ "abc", "pqr", 0 },
};
int i = 0;
for (i = 0; i < ARRAY_SIZE(cases); i++) {
struct strbuf a = STRBUF_INIT;
struct strbuf b = STRBUF_INIT;
strbuf_addstr(&a, cases[i].a);
strbuf_addstr(&b, cases[i].b);
EXPECT(common_prefix_size(&a, &b) == cases[i].want);
strbuf_release(&a);
strbuf_release(&b);
}
}
static void set_hash(uint8_t *h, int j)
{
int i = 0;
for (i = 0; i < hash_size(GIT_SHA1_FORMAT_ID); i++) {
h[i] = (j >> i) & 0xff;
}
}
static void test_reftable_ref_record_roundtrip(void)
{
int i = 0;
for (i = REFTABLE_REF_DELETION; i < REFTABLE_NR_REF_VALUETYPES; i++) {
struct reftable_ref_record in = { NULL };
struct reftable_ref_record out = { NULL };
struct reftable_record rec_out = { NULL };
struct strbuf key = STRBUF_INIT;
struct reftable_record rec = { NULL };
uint8_t buffer[1024] = { 0 };
struct string_view dest = {
.buf = buffer,
.len = sizeof(buffer),
};
int n, m;
in.value_type = i;
switch (i) {
case REFTABLE_REF_DELETION:
break;
case REFTABLE_REF_VAL1:
in.value.val1 = reftable_malloc(GIT_SHA1_RAWSZ);
set_hash(in.value.val1, 1);
break;
case REFTABLE_REF_VAL2:
in.value.val2.value = reftable_malloc(GIT_SHA1_RAWSZ);
set_hash(in.value.val2.value, 1);
in.value.val2.target_value =
reftable_malloc(GIT_SHA1_RAWSZ);
set_hash(in.value.val2.target_value, 2);
break;
case REFTABLE_REF_SYMREF:
in.value.symref = xstrdup("target");
break;
}
in.refname = xstrdup("refs/heads/master");
reftable_record_from_ref(&rec, &in);
test_copy(&rec);
EXPECT(reftable_record_val_type(&rec) == i);
reftable_record_key(&rec, &key);
n = reftable_record_encode(&rec, dest, GIT_SHA1_RAWSZ);
EXPECT(n > 0);
/* decode into a non-zero reftable_record to test for leaks. */
reftable_record_from_ref(&rec_out, &out);
m = reftable_record_decode(&rec_out, key, i, dest,
GIT_SHA1_RAWSZ);
EXPECT(n == m);
EXPECT(reftable_ref_record_equal(&in, &out, GIT_SHA1_RAWSZ));
reftable_record_release(&rec_out);
strbuf_release(&key);
reftable_ref_record_release(&in);
}
}
static void test_reftable_log_record_equal(void)
{
struct reftable_log_record in[2] = {
{
.refname = xstrdup("refs/heads/master"),
.update_index = 42,
},
{
.refname = xstrdup("refs/heads/master"),
.update_index = 22,
}
};
EXPECT(!reftable_log_record_equal(&in[0], &in[1], GIT_SHA1_RAWSZ));
in[1].update_index = in[0].update_index;
EXPECT(reftable_log_record_equal(&in[0], &in[1], GIT_SHA1_RAWSZ));
reftable_log_record_release(&in[0]);
reftable_log_record_release(&in[1]);
}
static void test_reftable_log_record_roundtrip(void)
{
int i;
struct reftable_log_record in[2] = {
{
.refname = xstrdup("refs/heads/master"),
.update_index = 42,
.value_type = REFTABLE_LOG_UPDATE,
.value = {
.update = {
.old_hash = reftable_malloc(GIT_SHA1_RAWSZ),
.new_hash = reftable_malloc(GIT_SHA1_RAWSZ),
.name = xstrdup("han-wen"),
.email = xstrdup("hanwen@google.com"),
.message = xstrdup("test"),
.time = 1577123507,
.tz_offset = 100,
},
}
},
{
.refname = xstrdup("refs/heads/master"),
.update_index = 22,
.value_type = REFTABLE_LOG_DELETION,
}
};
set_test_hash(in[0].value.update.new_hash, 1);
set_test_hash(in[0].value.update.old_hash, 2);
for (i = 0; i < ARRAY_SIZE(in); i++) {
struct reftable_record rec = { NULL };
struct strbuf key = STRBUF_INIT;
uint8_t buffer[1024] = { 0 };
struct string_view dest = {
.buf = buffer,
.len = sizeof(buffer),
};
/* populate out, to check for leaks. */
struct reftable_log_record out = {
.refname = xstrdup("old name"),
.value_type = REFTABLE_LOG_UPDATE,
.value = {
.update = {
.new_hash = reftable_calloc(GIT_SHA1_RAWSZ),
.old_hash = reftable_calloc(GIT_SHA1_RAWSZ),
.name = xstrdup("old name"),
.email = xstrdup("old@email"),
.message = xstrdup("old message"),
},
},
};
struct reftable_record rec_out = { NULL };
int n, m, valtype;
reftable_record_from_log(&rec, &in[i]);
test_copy(&rec);
reftable_record_key(&rec, &key);
n = reftable_record_encode(&rec, dest, GIT_SHA1_RAWSZ);
EXPECT(n >= 0);
reftable_record_from_log(&rec_out, &out);
valtype = reftable_record_val_type(&rec);
m = reftable_record_decode(&rec_out, key, valtype, dest,
GIT_SHA1_RAWSZ);
EXPECT(n == m);
EXPECT(reftable_log_record_equal(&in[i], &out, GIT_SHA1_RAWSZ));
reftable_log_record_release(&in[i]);
strbuf_release(&key);
reftable_record_release(&rec_out);
}
}
static void test_u24_roundtrip(void)
{
uint32_t in = 0x112233;
uint8_t dest[3];
uint32_t out;
put_be24(dest, in);
out = get_be24(dest);
EXPECT(in == out);
}
static void test_key_roundtrip(void)
{
uint8_t buffer[1024] = { 0 };
struct string_view dest = {
.buf = buffer,
.len = sizeof(buffer),
};
struct strbuf last_key = STRBUF_INIT;
struct strbuf key = STRBUF_INIT;
struct strbuf roundtrip = STRBUF_INIT;
int restart;
uint8_t extra;
int n, m;
uint8_t rt_extra;
strbuf_addstr(&last_key, "refs/heads/master");
strbuf_addstr(&key, "refs/tags/bla");
extra = 6;
n = reftable_encode_key(&restart, dest, last_key, key, extra);
EXPECT(!restart);
EXPECT(n > 0);
m = reftable_decode_key(&roundtrip, &rt_extra, last_key, dest);
EXPECT(n == m);
EXPECT(0 == strbuf_cmp(&key, &roundtrip));
EXPECT(rt_extra == extra);
strbuf_release(&last_key);
strbuf_release(&key);
strbuf_release(&roundtrip);
}
static void test_reftable_obj_record_roundtrip(void)
{
uint8_t testHash1[GIT_SHA1_RAWSZ] = { 1, 2, 3, 4, 0 };
uint64_t till9[] = { 1, 2, 3, 4, 500, 600, 700, 800, 9000 };
struct reftable_obj_record recs[3] = { {
.hash_prefix = testHash1,
.hash_prefix_len = 5,
.offsets = till9,
.offset_len = 3,
},
{
.hash_prefix = testHash1,
.hash_prefix_len = 5,
.offsets = till9,
.offset_len = 9,
},
{
.hash_prefix = testHash1,
.hash_prefix_len = 5,
} };
int i = 0;
for (i = 0; i < ARRAY_SIZE(recs); i++) {
struct reftable_obj_record in = recs[i];
uint8_t buffer[1024] = { 0 };
struct string_view dest = {
.buf = buffer,
.len = sizeof(buffer),
};
struct reftable_record rec = { NULL };
struct strbuf key = STRBUF_INIT;
struct reftable_obj_record out = { NULL };
struct reftable_record rec_out = { NULL };
int n, m;
uint8_t extra;
reftable_record_from_obj(&rec, &in);
test_copy(&rec);
reftable_record_key(&rec, &key);
n = reftable_record_encode(&rec, dest, GIT_SHA1_RAWSZ);
EXPECT(n > 0);
extra = reftable_record_val_type(&rec);
reftable_record_from_obj(&rec_out, &out);
m = reftable_record_decode(&rec_out, key, extra, dest,
GIT_SHA1_RAWSZ);
EXPECT(n == m);
EXPECT(in.hash_prefix_len == out.hash_prefix_len);
EXPECT(in.offset_len == out.offset_len);
EXPECT(!memcmp(in.hash_prefix, out.hash_prefix,
in.hash_prefix_len));
EXPECT(0 == memcmp(in.offsets, out.offsets,
sizeof(uint64_t) * in.offset_len));
strbuf_release(&key);
reftable_record_release(&rec_out);
}
}
static void test_reftable_index_record_roundtrip(void)
{
struct reftable_index_record in = {
.offset = 42,
.last_key = STRBUF_INIT,
};
uint8_t buffer[1024] = { 0 };
struct string_view dest = {
.buf = buffer,
.len = sizeof(buffer),
};
struct strbuf key = STRBUF_INIT;
struct reftable_record rec = { NULL };
struct reftable_index_record out = { .last_key = STRBUF_INIT };
struct reftable_record out_rec = { NULL };
int n, m;
uint8_t extra;
strbuf_addstr(&in.last_key, "refs/heads/master");
reftable_record_from_index(&rec, &in);
reftable_record_key(&rec, &key);
test_copy(&rec);
EXPECT(0 == strbuf_cmp(&key, &in.last_key));
n = reftable_record_encode(&rec, dest, GIT_SHA1_RAWSZ);
EXPECT(n > 0);
extra = reftable_record_val_type(&rec);
reftable_record_from_index(&out_rec, &out);
m = reftable_record_decode(&out_rec, key, extra, dest, GIT_SHA1_RAWSZ);
EXPECT(m == n);
EXPECT(in.offset == out.offset);
reftable_record_release(&out_rec);
strbuf_release(&key);
strbuf_release(&in.last_key);
}
int record_test_main(int argc, const char *argv[])
{
RUN_TEST(test_reftable_log_record_equal);
RUN_TEST(test_reftable_log_record_roundtrip);
RUN_TEST(test_reftable_ref_record_roundtrip);
RUN_TEST(test_varint_roundtrip);
RUN_TEST(test_key_roundtrip);
RUN_TEST(test_common_prefix);
RUN_TEST(test_reftable_obj_record_roundtrip);
RUN_TEST(test_reftable_index_record_roundtrip);
RUN_TEST(test_u24_roundtrip);
return 0;
}

114
reftable/reftable-record.h Normal file
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@ -0,0 +1,114 @@
/*
Copyright 2020 Google LLC
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file or at
https://developers.google.com/open-source/licenses/bsd
*/
#ifndef REFTABLE_RECORD_H
#define REFTABLE_RECORD_H
#include <stdint.h>
/*
* Basic data types
*
* Reftables store the state of each ref in struct reftable_ref_record, and they
* store a sequence of reflog updates in struct reftable_log_record.
*/
/* reftable_ref_record holds a ref database entry target_value */
struct reftable_ref_record {
char *refname; /* Name of the ref, malloced. */
uint64_t update_index; /* Logical timestamp at which this value is
* written */
enum {
/* tombstone to hide deletions from earlier tables */
REFTABLE_REF_DELETION = 0x0,
/* a simple ref */
REFTABLE_REF_VAL1 = 0x1,
/* a tag, plus its peeled hash */
REFTABLE_REF_VAL2 = 0x2,
/* a symbolic reference */
REFTABLE_REF_SYMREF = 0x3,
#define REFTABLE_NR_REF_VALUETYPES 4
} value_type;
union {
uint8_t *val1; /* malloced hash. */
struct {
uint8_t *value; /* first value, malloced hash */
uint8_t *target_value; /* second value, malloced hash */
} val2;
char *symref; /* referent, malloced 0-terminated string */
} value;
};
/* Returns the first hash, or NULL if `rec` is not of type
* REFTABLE_REF_VAL1 or REFTABLE_REF_VAL2. */
uint8_t *reftable_ref_record_val1(struct reftable_ref_record *rec);
/* Returns the second hash, or NULL if `rec` is not of type
* REFTABLE_REF_VAL2. */
uint8_t *reftable_ref_record_val2(struct reftable_ref_record *rec);
/* returns whether 'ref' represents a deletion */
int reftable_ref_record_is_deletion(const struct reftable_ref_record *ref);
/* prints a reftable_ref_record onto stdout. Useful for debugging. */
void reftable_ref_record_print(struct reftable_ref_record *ref,
uint32_t hash_id);
/* frees and nulls all pointer values inside `ref`. */
void reftable_ref_record_release(struct reftable_ref_record *ref);
/* returns whether two reftable_ref_records are the same. Useful for testing. */
int reftable_ref_record_equal(struct reftable_ref_record *a,
struct reftable_ref_record *b, int hash_size);
/* reftable_log_record holds a reflog entry */
struct reftable_log_record {
char *refname;
uint64_t update_index; /* logical timestamp of a transactional update.
*/
enum {
/* tombstone to hide deletions from earlier tables */
REFTABLE_LOG_DELETION = 0x0,
/* a simple update */
REFTABLE_LOG_UPDATE = 0x1,
#define REFTABLE_NR_LOG_VALUETYPES 2
} value_type;
union {
struct {
uint8_t *new_hash;
uint8_t *old_hash;
char *name;
char *email;
uint64_t time;
int16_t tz_offset;
char *message;
} update;
} value;
};
/* returns whether 'ref' represents the deletion of a log record. */
int reftable_log_record_is_deletion(const struct reftable_log_record *log);
/* frees and nulls all pointer values. */
void reftable_log_record_release(struct reftable_log_record *log);
/* returns whether two records are equal. Useful for testing. */
int reftable_log_record_equal(struct reftable_log_record *a,
struct reftable_log_record *b, int hash_size);
/* dumps a reftable_log_record on stdout, for debugging/testing. */
void reftable_log_record_print(struct reftable_log_record *log,
uint32_t hash_id);
#endif

2
t/helper/test-reftable.c
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@ -4,6 +4,6 @@
int cmd__reftable(int argc, const char **argv)
{
basics_test_main(argc, argv);
record_test_main(argc, argv);
return 0;
}