database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-23 14:01:44 +03:00
Code Activity

Improve API of GenericXLogRegister().

Browse Source 
Rename this function to GenericXLogRegisterBuffer() to make it clearer
what it does, and leave room for other sorts of "register" actions in
future.  Also, replace its "bool isNew" argument with an integer flags
argument, so as to allow adding more flags in future without an API
break.

Alexander Korotkov, adjusted slightly by me
This commit is contained in:
Tom Lane
2016-04-12 11:42:06 -04:00
parent bdf7db8192
commit 5713f03973
6 changed files with 41 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
src/backend/access/transam/generic_xlog.c
View File

@ -50,7 +50,7 @@
typedef struct
{
Buffer buffer; /* registered buffer */
bool fullImage; /* are we taking a full image of this page? */
int flags; /* flags for this buffer */
int deltaLen; /* space consumed in delta field */
char image[BLCKSZ]; /* copy of page image for modification */
char delta[MAX_DELTA_SIZE]; /* delta between page images */
@ -280,9 +280,11 @@ GenericXLogStart(Relation relation)
* is what the caller should modify.
*
* If the buffer is already registered, just return its existing entry.
* (It's not very clear what to do with the flags in such a case, but
* for now we stay with the original flags.)
*/
Page
GenericXLogRegister(GenericXLogState *state, Buffer buffer, bool isNew)
GenericXLogRegisterBuffer(GenericXLogState *state, Buffer buffer, int flags)
{
int block_id;
@ -295,7 +297,7 @@ GenericXLogRegister(GenericXLogState *state, Buffer buffer, bool isNew)
{
/* Empty slot, so use it (there cannot be a match later) */
page->buffer = buffer;
page->fullImage = isNew;
page->flags = flags;
memcpy(page->image,
BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST),
BLCKSZ);
@ -347,7 +349,7 @@ GenericXLogFinish(GenericXLogState *state)
BGP_NO_SNAPSHOT_TEST);
pageHeader = (PageHeader) pageData->image;
if (pageData->fullImage)
if (pageData->flags & GENERIC_XLOG_FULL_IMAGE)
{
/*
* A full-page image does not require us to supply any xlog

7
src/include/access/generic_xlog.h
View File

@ -22,14 +22,17 @@
#define MAX_GENERIC_XLOG_PAGES XLR_NORMAL_MAX_BLOCK_ID
/* Flag bits for GenericXLogRegisterBuffer */
#define GENERIC_XLOG_FULL_IMAGE 0x0001 /* write full-page image */
/* state of generic xlog record construction */
struct GenericXLogState;
typedef struct GenericXLogState GenericXLogState;
/* API for construction of generic xlog records */
extern GenericXLogState *GenericXLogStart(Relation relation);
extern Page GenericXLogRegister(GenericXLogState *state, Buffer buffer,
bool isNew);
extern Page GenericXLogRegisterBuffer(GenericXLogState *state, Buffer buffer,
int flags);
extern XLogRecPtr GenericXLogFinish(GenericXLogState *state);
extern void GenericXLogAbort(GenericXLogState *state);