From 35d5ed7cb9149a9d02829204fdc52ff9437b36a9 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Wed, 13 Sep 2017 18:39:24 -0700 Subject: [PATCH 2/8] Add more efficient functions to pqformat API. New inline functions allow to add data to a stringbuf in a more efficient manner by pre-allocating ahead of time, and pq_beginmessage_pre/pq_endmessage_keep allow reuse of a stringbuffer. --- src/backend/libpq/pqformat.c | 37 +++++++++++++++++++++++++++++++++ src/backend/utils/mb/mbutils.c | 11 ---------- src/include/libpq/pqformat.h | 47 ++++++++++++++++++++++++++++++++++++++++++ src/include/mb/pg_wchar.h | 11 ++++++++++ 4 files changed, 95 insertions(+), 11 deletions(-) diff --git a/src/backend/libpq/pqformat.c b/src/backend/libpq/pqformat.c index c8cf67c041..6e40ee087c 100644 --- a/src/backend/libpq/pqformat.c +++ b/src/backend/libpq/pqformat.c @@ -97,6 +97,28 @@ pq_beginmessage(StringInfo buf, char msgtype) buf->cursor = msgtype; } +/* -------------------------------- + + * pq_beginmessage_pre - initialize for sending a message, reuse buffer + * + * This requires the buffer to be allocated in an sufficiently long-lived + * memory context. + * -------------------------------- + */ +void +pq_beginmessage_pre(StringInfo buf, char msgtype) +{ + resetStringInfo(buf); + + /* + * We stash the message type into the buffer's cursor field, expecting + * that the pq_sendXXX routines won't touch it. We could alternatively + * make it the first byte of the buffer contents, but this seems easier. + */ + buf->cursor = msgtype; +} + + /* -------------------------------- * pq_sendbyte - append a raw byte to a StringInfo buffer * -------------------------------- @@ -350,6 +372,21 @@ pq_endmessage(StringInfo buf) buf->data = NULL; } +/* -------------------------------- + * pq_endmessage_keep - send the completed message to the frontend + * + * The data buffer is *not* freed, allowing to reuse the buffer with + * pg_beginmessage_pre. + -------------------------------- + */ + +void +pq_endmessage_keep(StringInfo buf) +{ + /* msgtype was saved in cursor field */ + (void) pq_putmessage(buf->cursor, buf->data, buf->len); +} + /* -------------------------------- * pq_begintypsend - initialize for constructing a bytea result diff --git a/src/backend/utils/mb/mbutils.c b/src/backend/utils/mb/mbutils.c index c4fbe0903b..56f4dc1453 100644 --- a/src/backend/utils/mb/mbutils.c +++ b/src/backend/utils/mb/mbutils.c @@ -41,17 +41,6 @@ #include "utils/memutils.h" #include "utils/syscache.h" -/* - * When converting strings between different encodings, we assume that space - * for converted result is 4-to-1 growth in the worst case. The rate for - * currently supported encoding pairs are within 3 (SJIS JIS X0201 half width - * kanna -> UTF8 is the worst case). So "4" should be enough for the moment. - * - * Note that this is not the same as the maximum character width in any - * particular encoding. - */ -#define MAX_CONVERSION_GROWTH 4 - /* * We maintain a simple linked list caching the fmgr lookup info for the * currently selected conversion functions, as well as any that have been diff --git a/src/include/libpq/pqformat.h b/src/include/libpq/pqformat.h index 32112547a0..2e5b2b7685 100644 --- a/src/include/libpq/pqformat.h +++ b/src/include/libpq/pqformat.h @@ -14,8 +14,10 @@ #define PQFORMAT_H #include "lib/stringinfo.h" +#include "mb/pg_wchar.h" extern void pq_beginmessage(StringInfo buf, char msgtype); +extern void pq_beginmessage_pre(StringInfo buf, char msgtype); extern void pq_sendbyte(StringInfo buf, int byt); extern void pq_sendbytes(StringInfo buf, const char *data, int datalen); extern void pq_sendcountedtext(StringInfo buf, const char *str, int slen, @@ -28,6 +30,51 @@ extern void pq_sendint64(StringInfo buf, int64 i); extern void pq_sendfloat4(StringInfo buf, float4 f); extern void pq_sendfloat8(StringInfo buf, float8 f); extern void pq_endmessage(StringInfo buf); +extern void pq_endmessage_keep(StringInfo buf); + +extern void pq_sendint64(StringInfo buf, int64 i); +extern void pq_sendfloat4(StringInfo buf, float4 f); +extern void pq_sendfloat8(StringInfo buf, float8 f); + +/* inline versions that require all space is pre-allocated */ +static inline void +pq_sendint32_pre(StringInfo buf, int32 i) +{ + Assert(buf->len + sizeof(i) + 1 <= buf->maxlen); + *(int32* ) (buf->data + buf->len) = htonl(i); + buf->len += sizeof(i); + *(char *) (buf->data + buf->len) = '\0'; +} + +static inline void +pq_sendint16_pre(StringInfo buf, int16 i) +{ + Assert(buf->len + sizeof(i) + 1 <= buf->maxlen); + *(int16* ) (buf->data + buf->len) = htons(i); + buf->len += sizeof(i); + *(char *) (buf->data + buf->len) = '\0'; +} + +static inline void +pq_sendstring_pre(StringInfo buf, const char *str) +{ + int slen = strlen(str); + char *p; + + p = pg_server_to_client(str, slen); + if (p != str) /* actual conversion has been done? */ + slen = strlen(p); + + Assert(buf->len + slen + 1 <= buf->maxlen); + + memcpy(buf->data + buf->len, p, slen + 1); + buf->len += slen + 1; + *(char *) (buf->data + buf->len) = '\0'; + + if (p != str) + pfree(p); +} + extern void pq_begintypsend(StringInfo buf); extern bytea *pq_endtypsend(StringInfo buf); diff --git a/src/include/mb/pg_wchar.h b/src/include/mb/pg_wchar.h index d57ef017cb..9227d634f6 100644 --- a/src/include/mb/pg_wchar.h +++ b/src/include/mb/pg_wchar.h @@ -304,6 +304,17 @@ typedef enum pg_enc /* On FE are possible all encodings */ #define PG_VALID_FE_ENCODING(_enc) PG_VALID_ENCODING(_enc) +/* + * When converting strings between different encodings, we assume that space + * for converted result is 4-to-1 growth in the worst case. The rate for + * currently supported encoding pairs are within 3 (SJIS JIS X0201 half width + * kanna -> UTF8 is the worst case). So "4" should be enough for the moment. + * + * Note that this is not the same as the maximum character width in any + * particular encoding. + */ +#define MAX_CONVERSION_GROWTH 4 + /* * Table for mapping an encoding number to official encoding name and * possibly other subsidiary data. Be careful to check encoding number -- 2.14.1.536.g6867272d5b.dirty