[Tarantool-patches] [PATCH v3 4/6] iproto: refactor error encoding with mpstream
Nikita Pettik
korablev at tarantool.org
Mon Apr 6 17:17:13 MSK 2020
From: Kirill Shcherbatov <kshcherbatov at tarantool.org>
Refactor iproto_reply_error and iproto_write_error with a new
mpstream-based helper mpstream_iproto_encode_error that encodes
error object for iproto protocol on a given stream object.
Previously each routine implemented an own error encoding, but
with the increasing complexity of encode operation with following
patches we need a uniform way to do it.
The iproto_write_error routine starts using region location
to use region-based mpstream. It is not a problem itself, because
errors reporting is not really performance-critical path.
Needed for #1148
---
src/box/xrow.c | 70 +++++++++++++++++++++++++++++++++++---------------
1 file changed, 49 insertions(+), 21 deletions(-)
diff --git a/src/box/xrow.c b/src/box/xrow.c
index 5e3cb0709..28adbdc1f 100644
--- a/src/box/xrow.c
+++ b/src/box/xrow.c
@@ -42,6 +42,7 @@
#include "vclock.h"
#include "scramble.h"
#include "iproto_constants.h"
+#include "mpstream.h"
static_assert(IPROTO_DATA < 0x7f && IPROTO_METADATA < 0x7f &&
IPROTO_SQL_INFO < 0x7f, "encoded IPROTO_BODY keys must fit into "\
@@ -381,10 +382,6 @@ static const struct iproto_body_bin iproto_body_bin = {
0x81, IPROTO_DATA, 0xdd, 0
};
-static const struct iproto_body_bin iproto_error_bin = {
- 0x81, IPROTO_ERROR, 0xdb, 0
-};
-
/** Return a 4-byte numeric error code, with status flags. */
static inline uint32_t
iproto_encode_error(uint32_t error)
@@ -478,46 +475,77 @@ iproto_reply_vote(struct obuf *out, const struct ballot *ballot,
return 0;
}
+static void
+mpstream_error_handler(void *error_ctx)
+{
+ *(bool *)error_ctx = true;
+}
+
+static void
+mpstream_iproto_encode_error(struct mpstream *stream, const struct error *error)
+{
+ mpstream_encode_map(stream, 2);
+ mpstream_encode_uint(stream, IPROTO_ERROR);
+ mpstream_encode_str(stream, error->errmsg);
+}
+
int
iproto_reply_error(struct obuf *out, const struct error *e, uint64_t sync,
uint32_t schema_version)
{
- uint32_t msg_len = strlen(e->errmsg);
- uint32_t errcode = box_error_code(e);
-
- struct iproto_body_bin body = iproto_error_bin;
char *header = (char *)obuf_alloc(out, IPROTO_HEADER_LEN);
if (header == NULL)
return -1;
+ bool is_error = false;
+ struct mpstream stream;
+ mpstream_init(&stream, out, obuf_reserve_cb, obuf_alloc_cb,
+ mpstream_error_handler, &is_error);
+
+ uint32_t used = obuf_size(out);
+ mpstream_iproto_encode_error(&stream, e);
+ mpstream_flush(&stream);
+
+ uint32_t errcode = box_error_code(e);
iproto_header_encode(header, iproto_encode_error(errcode), sync,
- schema_version, sizeof(body) + msg_len);
- body.v_data_len = mp_bswap_u32(msg_len);
+ schema_version, obuf_size(out) - used);
+
/* Malformed packet appears to be a lesser evil than abort. */
- return obuf_dup(out, &body, sizeof(body)) != sizeof(body) ||
- obuf_dup(out, e->errmsg, msg_len) != msg_len ? -1 : 0;
+ return is_error ? -1 : 0;
}
void
iproto_write_error(int fd, const struct error *e, uint32_t schema_version,
uint64_t sync)
{
- uint32_t msg_len = strlen(e->errmsg);
- uint32_t errcode = box_error_code(e);
+ bool is_error = false;
+ struct mpstream stream;
+ struct region *region = &fiber()->gc;
+ mpstream_init(&stream, region, region_reserve_cb, region_alloc_cb,
+ mpstream_error_handler, &is_error);
+
+ size_t region_svp = region_used(region);
+ mpstream_iproto_encode_error(&stream, e);
+ mpstream_flush(&stream);
+ if (is_error)
+ goto cleanup;
+
+ size_t payload_size = region_used(region) - region_svp;
+ char *payload = region_join(region, payload_size);
+ if (payload == NULL)
+ goto cleanup;
+ uint32_t errcode = box_error_code(e);
char header[IPROTO_HEADER_LEN];
- struct iproto_body_bin body = iproto_error_bin;
-
iproto_header_encode(header, iproto_encode_error(errcode), sync,
- schema_version, sizeof(body) + msg_len);
-
- body.v_data_len = mp_bswap_u32(msg_len);
+ schema_version, payload_size);
ssize_t unused;
unused = write(fd, header, sizeof(header));
- unused = write(fd, &body, sizeof(body));
- unused = write(fd, e->errmsg, msg_len);
+ unused = write(fd, payload, payload_size);
(void) unused;
+cleanup:
+ region_truncate(region, region_svp);
}
int
--
2.17.1
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