From 20b386ca1794421ec0f2aaf81a08ab6f0ed2d9e2 Mon Sep 17 00:00:00 2001 From: David Rowley Date: Sat, 10 Dec 2022 20:27:01 +1300 Subject: [PATCH v2] Speed up creation of command completion tags Author: David Rowley, Andres Freund --- src/backend/tcop/cmdtag.c | 73 +++++++++++++++++++++++++++++++++++++-- src/backend/tcop/dest.c | 29 +++------------- src/include/tcop/cmdtag.h | 5 +++ src/include/tcop/dest.h | 2 -- 4 files changed, 79 insertions(+), 30 deletions(-) diff --git a/src/backend/tcop/cmdtag.c b/src/backend/tcop/cmdtag.c index 262484f561..8e52ff084a 100644 --- a/src/backend/tcop/cmdtag.c +++ b/src/backend/tcop/cmdtag.c @@ -15,18 +15,22 @@ #include "miscadmin.h" #include "tcop/cmdtag.h" +#include "utils/builtins.h" typedef struct CommandTagBehavior { - const char *name; + const char *name; /* tag name, e.g. "SELECT" */ + const uint8 namelen; /* set to strlen(name) */ const bool event_trigger_ok; const bool table_rewrite_ok; - const bool display_rowcount; + const bool display_rowcount; /* should the number of rows affected be + * shown in the command completion string + */ } CommandTagBehavior; #define PG_CMDTAG(tag, name, evtrgok, rwrok, rowcnt) \ - { name, evtrgok, rwrok, rowcnt }, + { name, (uint8) (sizeof(name) - 1), evtrgok, rwrok, rowcnt }, static const CommandTagBehavior tag_behavior[COMMAND_TAG_NEXTTAG] = { #include "tcop/cmdtaglist.h" @@ -47,6 +51,13 @@ GetCommandTagName(CommandTag commandTag) return tag_behavior[commandTag].name; } +const char * +GetCommandTagNameAndLen(CommandTag commandTag, Size *len) +{ + *len = (Size) tag_behavior[commandTag].namelen; + return tag_behavior[commandTag].name; +} + bool command_tag_display_rowcount(CommandTag commandTag) { @@ -96,3 +107,59 @@ GetCommandTagEnum(const char *commandname) } return CMDTAG_UNKNOWN; } + +/* + * BuildQueryCompletionString + * Build a string containing the command tag name with the + * QueryCompletion's nprocessed for command tags with display_rowcount + * set. Returns the strlen of the constructed string. + * + * The caller must ensure that buff is at least COMPLETION_TAG_BUFSIZE bytes. + * + * If nameonly is true, then the constructed string will contain only the tag + * name. + */ +Size +BuildQueryCompletionString(char *buff, const QueryCompletion *qc, + bool nameonly) +{ + CommandTag tag = qc->commandTag; + Size taglen; + const char *tagname = GetCommandTagNameAndLen(tag, &taglen); + char *bufp; + + /* + * We assume the tagname is plain ASCII and therefore requires no encoding + * conversion. + */ + memcpy(buff, tagname, taglen); + bufp = buff + taglen; + + /* ensure that the tagname isn't long enough to overrun the buffer */ + Assert(taglen <= COMPLETION_TAG_BUFSIZE - MAXINT8LEN - 4); + + /* + * In PostgreSQL versions 11 and earlier, it was possible to create a + * table WITH OIDS. When inserting into such a table, INSERT used to + * include the Oid of the inserted record in the completion tag. To + * maintain compatibility in the wire protocol, we now write a "0" (for + * InvalidOid) in the location where we once wrote the new record's Oid. + */ + if (command_tag_display_rowcount(tag) && !nameonly) + { + if (tag == CMDTAG_INSERT) + { + *bufp++ = ' '; + *bufp++ = '0'; + } + *bufp++ = ' '; + bufp += pg_ulltoa_n(qc->nprocessed, bufp); + } + + /* and finally, NUL terminate the string */ + *bufp = '\0'; + + Assert((bufp - buff) == strlen(buff)); + + return bufp - buff; +} diff --git a/src/backend/tcop/dest.c b/src/backend/tcop/dest.c index 6afaa153ca..e879304ae1 100644 --- a/src/backend/tcop/dest.c +++ b/src/backend/tcop/dest.c @@ -166,8 +166,7 @@ void EndCommand(const QueryCompletion *qc, CommandDest dest, bool force_undecorated_output) { char completionTag[COMPLETION_TAG_BUFSIZE]; - CommandTag tag; - const char *tagname; + Size len; switch (dest) { @@ -175,29 +174,9 @@ EndCommand(const QueryCompletion *qc, CommandDest dest, bool force_undecorated_o case DestRemoteExecute: case DestRemoteSimple: - /* - * We assume the tagname is plain ASCII and therefore requires no - * encoding conversion. - */ - tag = qc->commandTag; - tagname = GetCommandTagName(tag); - - /* - * In PostgreSQL versions 11 and earlier, it was possible to - * create a table WITH OIDS. When inserting into such a table, - * INSERT used to include the Oid of the inserted record in the - * completion tag. To maintain compatibility in the wire - * protocol, we now write a "0" (for InvalidOid) in the location - * where we once wrote the new record's Oid. - */ - if (command_tag_display_rowcount(tag) && !force_undecorated_output) - snprintf(completionTag, COMPLETION_TAG_BUFSIZE, - tag == CMDTAG_INSERT ? - "%s 0 " UINT64_FORMAT : "%s " UINT64_FORMAT, - tagname, qc->nprocessed); - else - snprintf(completionTag, COMPLETION_TAG_BUFSIZE, "%s", tagname); - pq_putmessage('C', completionTag, strlen(completionTag) + 1); + len = BuildQueryCompletionString(completionTag, qc, + force_undecorated_output); + pq_putmessage('C', completionTag, len + 1); case DestNone: case DestDebug: diff --git a/src/include/tcop/cmdtag.h b/src/include/tcop/cmdtag.h index 60e3179c74..a45d71d0cb 100644 --- a/src/include/tcop/cmdtag.h +++ b/src/include/tcop/cmdtag.h @@ -13,6 +13,8 @@ #ifndef CMDTAG_H #define CMDTAG_H + /* buffer size required for command completion tags */ +#define COMPLETION_TAG_BUFSIZE 64 #define PG_CMDTAG(tag, name, evtrgok, rwrok, rowcnt) \ tag, @@ -50,9 +52,12 @@ CopyQueryCompletion(QueryCompletion *dst, const QueryCompletion *src) extern void InitializeQueryCompletion(QueryCompletion *qc); extern const char *GetCommandTagName(CommandTag commandTag); +extern const char *GetCommandTagNameAndLen(CommandTag commandTag, Size *len); extern bool command_tag_display_rowcount(CommandTag commandTag); extern bool command_tag_event_trigger_ok(CommandTag commandTag); extern bool command_tag_table_rewrite_ok(CommandTag commandTag); extern CommandTag GetCommandTagEnum(const char *commandname); +extern Size BuildQueryCompletionString(char *buff, const QueryCompletion *qc, + bool nameonly); #endif /* CMDTAG_H */ diff --git a/src/include/tcop/dest.h b/src/include/tcop/dest.h index 3c3eabae67..83d1af88b4 100644 --- a/src/include/tcop/dest.h +++ b/src/include/tcop/dest.h @@ -71,8 +71,6 @@ #include "tcop/cmdtag.h" -/* buffer size to use for command completion tags */ -#define COMPLETION_TAG_BUFSIZE 64 /* ---------------- -- 2.35.1.windows.2