*
* stringinfo.h
* Declarations/definitions for "StringInfo" functions.
*
* StringInfo provides an indefinitely-extensible string data type.
* It can be used to buffer either ordinary C strings (null-terminated text)
* or arbitrary binary data. All storage is allocated with palloc().
*
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
* Portions Copyright (c) 2010-2012 Postgres-XC Development Group
*
* IDENTIFICATION
* src/include/cm/stringinfo.h
*
* ---------------------------------------------------------------------------------------
*/
#ifndef CM_STRINGINFO_H
#define CM_STRINGINFO_H
#include <stdarg.h>
* StringInfoData holds information about an extensible string.
* data is the current buffer for the string (allocated with palloc).
* len is the current string length. There is guaranteed to be
* a terminating '\0' at data[len], although this is not very
* useful when the string holds binary data rather than text.
* maxlen is the allocated size in bytes of 'data', i.e. the maximum
* string size (including the terminating '\0' char) that we can
* currently store in 'data' without having to reallocate
* more space. We must always have maxlen > len.
* cursor is initialized to zero by makeStringInfo or initStringInfo,
* but is not otherwise touched by the stringinfo.c routines.
* Some routines use it to scan through a StringInfo.
*-------------------------
*/
typedef struct CM_StringInfoData {
char* data;
int len;
int maxlen;
int cursor;
int qtype;
int msglen;
} CM_StringInfoData;
typedef CM_StringInfoData* CM_StringInfo;
#define CM_MaxAllocSize ((Size)0x3fffffff)
#define CM_AllocSizeIsValid(size) ((Size)(size) <= CM_MaxAllocSize)
* There are two ways to create a StringInfo object initially:
*
* StringInfo stringptr = makeStringInfo();
* Both the StringInfoData and the data buffer are palloc'd.
*
* StringInfoData string;
* initStringInfo(&string);
* The data buffer is palloc'd but the StringInfoData is just local.
* This is the easiest approach for a StringInfo object that will
* only live as long as the current routine.
*
* To destroy a StringInfo, pfree() the data buffer, and then pfree() the
* StringInfoData if it was palloc'd. There's no special support for this.
*
* NOTE: some routines build up a string using StringInfo, and then
* release the StringInfoData but return the data string itself to their
* caller. At that point the data string looks like a plain palloc'd
* string.
*-------------------------
*/
* makeStringInfo
* Create an empty 'StringInfoData' & return a pointer to it.
*/
extern CM_StringInfo CM_makeStringInfo(void);
* initStringInfo
* Initialize a StringInfoData struct (with previously undefined contents)
* to describe an empty string.
*/
extern void CM_initStringInfo(CM_StringInfo str);
* resetStringInfo
* Clears the current content of the StringInfo, if any. The
* StringInfo remains valid.
*/
extern void CM_resetStringInfo(CM_StringInfo str);
* appendStringInfo
* Format text data under the control of fmt (an sprintf-style format string)
* and append it to whatever is already in str. More space is allocated
* to str if necessary. This is sort of like a combination of sprintf and
* strcat.
*/
extern void CM_appendStringInfo(CM_StringInfo str, const char* fmt, ...)
__attribute__((format(printf, 2, 3)));
* appendStringInfoVA
* Attempt to format text data under the control of fmt (an sprintf-style
* format string) and append it to whatever is already in str. If successful
* return true; if not (because there's not enough space), return false
* without modifying str. Typically the caller would enlarge str and retry
* on false return --- see appendStringInfo for standard usage pattern.
*/
extern bool CM_appendStringInfoVA(CM_StringInfo str, const char* fmt, va_list args)
__attribute__((format(printf, 2, 0)));
* appendStringInfoString
* Append a null-terminated string to str.
* Like appendStringInfo(str, "%s", s) but faster.
*/
extern void CM_appendStringInfoString(CM_StringInfo str, const char* s);
* appendStringInfoChar
* Append a single byte to str.
* Like appendStringInfo(str, "%c", ch) but much faster.
*/
extern void CM_appendStringInfoChar(CM_StringInfo str, char ch);
* appendStringInfoCharMacro
* As above, but a macro for even more speed where it matters.
* Caution: str argument will be evaluated multiple times.
*/
#define CM_appendStringInfoCharMacro(str, ch) \
(((str)->len + 1 >= (str)->maxlen) ? CM_appendStringInfoChar(str, ch) \
: (void)((str)->data[(str)->len] = (ch), (str)->data[++(str)->len] = '\0'))
* appendBinaryStringInfo
* Append arbitrary binary data to a StringInfo, allocating more space
* if necessary.
*/
extern void CM_appendBinaryStringInfo(CM_StringInfo str, const char* data, int datalen);
* enlargeStringInfo
* Make sure a StringInfo's buffer can hold at least 'needed' more bytes.
*/
extern int CM_enlargeStringInfo(CM_StringInfo str, int needed);
* dupStringInfo
* Get new StringInfo and copy the original to it.
*/
extern CM_StringInfo CM_dupStringInfo(CM_StringInfo orig);
* copyStringInfo
* Copy StringInfo. Deep copy: Data will be copied too.
* cursor of "to" will be initialized to zero.
*/
extern void CM_copyStringInfo(CM_StringInfo to, CM_StringInfo from);
extern int CM_is_str_all_digit(const char* name);
extern void CM_destroyStringInfo(CM_StringInfo str);
extern void CM_freeStringInfo(CM_StringInfo str);
#endif