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Second round of FE/BE protocol changes. Frontend->backend messages now

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have length counts, and COPY IN data is packetized into messages.
This commit is contained in:
Tom Lane
2003-04-19 00:02:30 +00:00
parent 54b38d293e
commit bd8d441775
24 changed files with 1337 additions and 982 deletions
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86
src/backend/lib/stringinfo.c
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@ -9,15 +9,15 @@
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: stringinfo.c,v 1.32 2002/09/04 20:31:18 momjian Exp $
* $Id: stringinfo.c,v 1.33 2003/04/19 00:02:29 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "lib/stringinfo.h"
/*
* makeStringInfo
*
@ -50,41 +50,7 @@ initStringInfo(StringInfo str)
str->maxlen = size;
str->len = 0;
str->data[0] = '\0';
}
/*
* enlargeStringInfo
*
* Internal routine: make sure there is enough space for 'needed' more bytes
* ('needed' does not include the terminating null).
*
* NB: because we use repalloc() to enlarge the buffer, the string buffer
* will remain allocated in the same memory context that was current when
* initStringInfo was called, even if another context is now current.
* This is the desired and indeed critical behavior!
*/
static void
enlargeStringInfo(StringInfo str, int needed)
{
int newlen;
needed += str->len + 1; /* total space required now */
if (needed <= str->maxlen)
return; /* got enough space already */
/*
* We don't want to allocate just a little more space with each
* append; for efficiency, double the buffer size each time it
* overflows. Actually, we might need to more than double it if
* 'needed' is big...
*/
newlen = 2 * str->maxlen;
while (needed > newlen)
newlen = 2 * newlen;
str->data = (char *) repalloc(str->data, newlen);
str->maxlen = newlen;
str->cursor = 0;
}
/*
@ -147,8 +113,9 @@ appendStringInfo(StringInfo str, const char *fmt,...)
}
}
/*------------------------
/*
* appendStringInfoChar
*
* Append a single byte to str.
* Like appendStringInfo(str, "%c", ch) but much faster.
*/
@ -189,3 +156,44 @@ appendBinaryStringInfo(StringInfo str, const char *data, int datalen)
*/
str->data[str->len] = '\0';
}
/*
* enlargeStringInfo
*
* Make sure there is enough space for 'needed' more bytes
* ('needed' does not include the terminating null).
*
* External callers need not concern themselves with this, since all
* stringinfo.c routines do it automatically. However, if a caller
* knows that a StringInfo will eventually become X bytes large, it
* can save some palloc overhead by enlarging the buffer before starting
* to store data in it.
*
* NB: because we use repalloc() to enlarge the buffer, the string buffer
* will remain allocated in the same memory context that was current when
* initStringInfo was called, even if another context is now current.
* This is the desired and indeed critical behavior!
*/
void
enlargeStringInfo(StringInfo str, int needed)
{
int newlen;
needed += str->len + 1; /* total space required now */
if (needed <= str->maxlen)
return; /* got enough space already */
/*
* We don't want to allocate just a little more space with each
* append; for efficiency, double the buffer size each time it
* overflows. Actually, we might need to more than double it if
* 'needed' is big...
*/
newlen = 2 * str->maxlen;
while (needed > newlen)
newlen = 2 * newlen;
str->data = (char *) repalloc(str->data, newlen);
str->maxlen = newlen;
}