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xlogreader.h File Reference
#include "access/transam.h"
#include "access/xlogrecord.h"
#include "storage/buf.h"
Include dependency graph for xlogreader.h:
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Data Structures

struct  WALOpenSegment
 
struct  WALSegmentContext
 
struct  XLogReaderRoutine
 
struct  DecodedBkpBlock
 
struct  DecodedXLogRecord
 
struct  XLogReaderState
 
struct  WALReadError
 

Macros

#define XL_ROUTINE(...)   &(XLogReaderRoutine){__VA_ARGS__}
 
#define XLogRecGetTotalLen(decoder)   ((decoder)->record->header.xl_tot_len)
 
#define XLogRecGetPrev(decoder)   ((decoder)->record->header.xl_prev)
 
#define XLogRecGetInfo(decoder)   ((decoder)->record->header.xl_info)
 
#define XLogRecGetRmid(decoder)   ((decoder)->record->header.xl_rmid)
 
#define XLogRecGetXid(decoder)   ((decoder)->record->header.xl_xid)
 
#define XLogRecGetOrigin(decoder)   ((decoder)->record->record_origin)
 
#define XLogRecGetTopXid(decoder)   ((decoder)->record->toplevel_xid)
 
#define XLogRecGetData(decoder)   ((decoder)->record->main_data)
 
#define XLogRecGetDataLen(decoder)   ((decoder)->record->main_data_len)
 
#define XLogRecHasAnyBlockRefs(decoder)   ((decoder)->record->max_block_id >= 0)
 
#define XLogRecMaxBlockId(decoder)   ((decoder)->record->max_block_id)
 
#define XLogRecGetBlock(decoder, i)   (&(decoder)->record->blocks[(i)])
 
#define XLogRecHasBlockRef(decoder, block_id)
 
#define XLogRecHasBlockImage(decoder, block_id)    ((decoder)->record->blocks[block_id].has_image)
 
#define XLogRecBlockImageApply(decoder, block_id)    ((decoder)->record->blocks[block_id].apply_image)
 
#define XLogRecHasBlockData(decoder, block_id)    ((decoder)->record->blocks[block_id].has_data)
 

Typedefs

typedef struct WALOpenSegment WALOpenSegment
 
typedef struct WALSegmentContext WALSegmentContext
 
typedef struct XLogReaderState XLogReaderState
 
typedef int(* XLogPageReadCB) (XLogReaderState *xlogreader, XLogRecPtr targetPagePtr, int reqLen, XLogRecPtr targetRecPtr, char *readBuf)
 
typedef void(* WALSegmentOpenCB) (XLogReaderState *xlogreader, XLogSegNo nextSegNo, TimeLineID *tli_p)
 
typedef void(* WALSegmentCloseCB) (XLogReaderState *xlogreader)
 
typedef struct XLogReaderRoutine XLogReaderRoutine
 
typedef struct DecodedXLogRecord DecodedXLogRecord
 
typedef enum XLogPageReadResult XLogPageReadResult
 
typedef struct WALReadError WALReadError
 

Enumerations

enum  XLogPageReadResult { XLREAD_SUCCESS = 0 , XLREAD_FAIL = -1 , XLREAD_WOULDBLOCK = -2 }
 

Functions

static bool XLogReaderHasQueuedRecordOrError (XLogReaderState *state)
 
XLogReaderStateXLogReaderAllocate (int wal_segment_size, const char *waldir, XLogReaderRoutine *routine, void *private_data)
 
void XLogReaderFree (XLogReaderState *state)
 
void XLogReaderSetDecodeBuffer (XLogReaderState *state, void *buffer, size_t size)
 
void XLogBeginRead (XLogReaderState *state, XLogRecPtr RecPtr)
 
XLogRecPtr XLogFindNextRecord (XLogReaderState *state, XLogRecPtr RecPtr)
 
struct XLogRecordXLogReadRecord (XLogReaderState *state, char **errormsg)
 
DecodedXLogRecordXLogNextRecord (XLogReaderState *state, char **errormsg)
 
XLogRecPtr XLogReleasePreviousRecord (XLogReaderState *state)
 
DecodedXLogRecordXLogReadAhead (XLogReaderState *state, bool nonblocking)
 
bool XLogReaderValidatePageHeader (XLogReaderState *state, XLogRecPtr recptr, char *phdr)
 
void XLogReaderResetError (XLogReaderState *state)
 
bool WALRead (XLogReaderState *state, char *buf, XLogRecPtr startptr, Size count, TimeLineID tli, WALReadError *errinfo)
 
size_t DecodeXLogRecordRequiredSpace (size_t xl_tot_len)
 
bool DecodeXLogRecord (XLogReaderState *state, DecodedXLogRecord *decoded, XLogRecord *record, XLogRecPtr lsn, char **errormsg)
 
FullTransactionId XLogRecGetFullXid (XLogReaderState *record)
 
bool RestoreBlockImage (XLogReaderState *record, uint8 block_id, char *page)
 
char * XLogRecGetBlockData (XLogReaderState *record, uint8 block_id, Size *len)
 
void XLogRecGetBlockTag (XLogReaderState *record, uint8 block_id, RelFileLocator *rlocator, ForkNumber *forknum, BlockNumber *blknum)
 
bool XLogRecGetBlockTagExtended (XLogReaderState *record, uint8 block_id, RelFileLocator *rlocator, ForkNumber *forknum, BlockNumber *blknum, Buffer *prefetch_buffer)
 

Macro Definition Documentation

◆ XL_ROUTINE

#define XL_ROUTINE (   ...)    &(XLogReaderRoutine){__VA_ARGS__}

Definition at line 117 of file xlogreader.h.

◆ XLogRecBlockImageApply

#define XLogRecBlockImageApply (   decoder,
  block_id 
)     ((decoder)->record->blocks[block_id].apply_image)

Definition at line 425 of file xlogreader.h.

◆ XLogRecGetBlock

#define XLogRecGetBlock (   decoder,
  i 
)    (&(decoder)->record->blocks[(i)])

Definition at line 419 of file xlogreader.h.

◆ XLogRecGetData

#define XLogRecGetData (   decoder)    ((decoder)->record->main_data)

Definition at line 415 of file xlogreader.h.

◆ XLogRecGetDataLen

#define XLogRecGetDataLen (   decoder)    ((decoder)->record->main_data_len)

Definition at line 416 of file xlogreader.h.

◆ XLogRecGetInfo

#define XLogRecGetInfo (   decoder)    ((decoder)->record->header.xl_info)

Definition at line 410 of file xlogreader.h.

◆ XLogRecGetOrigin

#define XLogRecGetOrigin (   decoder)    ((decoder)->record->record_origin)

Definition at line 413 of file xlogreader.h.

◆ XLogRecGetPrev

#define XLogRecGetPrev (   decoder)    ((decoder)->record->header.xl_prev)

Definition at line 409 of file xlogreader.h.

◆ XLogRecGetRmid

#define XLogRecGetRmid (   decoder)    ((decoder)->record->header.xl_rmid)

Definition at line 411 of file xlogreader.h.

◆ XLogRecGetTopXid

#define XLogRecGetTopXid (   decoder)    ((decoder)->record->toplevel_xid)

Definition at line 414 of file xlogreader.h.

◆ XLogRecGetTotalLen

#define XLogRecGetTotalLen (   decoder)    ((decoder)->record->header.xl_tot_len)

Definition at line 408 of file xlogreader.h.

◆ XLogRecGetXid

#define XLogRecGetXid (   decoder)    ((decoder)->record->header.xl_xid)

Definition at line 412 of file xlogreader.h.

◆ XLogRecHasAnyBlockRefs

#define XLogRecHasAnyBlockRefs (   decoder)    ((decoder)->record->max_block_id >= 0)

Definition at line 417 of file xlogreader.h.

◆ XLogRecHasBlockData

#define XLogRecHasBlockData (   decoder,
  block_id 
)     ((decoder)->record->blocks[block_id].has_data)

Definition at line 427 of file xlogreader.h.

◆ XLogRecHasBlockImage

#define XLogRecHasBlockImage (   decoder,
  block_id 
)     ((decoder)->record->blocks[block_id].has_image)

Definition at line 423 of file xlogreader.h.

◆ XLogRecHasBlockRef

#define XLogRecHasBlockRef (   decoder,
  block_id 
)
Value:
(((decoder)->record->max_block_id >= (block_id)) && \
((decoder)->record->blocks[block_id].in_use))

Definition at line 420 of file xlogreader.h.

◆ XLogRecMaxBlockId

#define XLogRecMaxBlockId (   decoder)    ((decoder)->record->max_block_id)

Definition at line 418 of file xlogreader.h.

Typedef Documentation

◆ DecodedXLogRecord

◆ WALOpenSegment

◆ WALReadError

typedef struct WALReadError WALReadError

◆ WALSegmentCloseCB

typedef void(* WALSegmentCloseCB) (XLogReaderState *xlogreader)

Definition at line 70 of file xlogreader.h.

◆ WALSegmentContext

◆ WALSegmentOpenCB

typedef void(* WALSegmentOpenCB) (XLogReaderState *xlogreader, XLogSegNo nextSegNo, TimeLineID *tli_p)

Definition at line 67 of file xlogreader.h.

◆ XLogPageReadCB

typedef int(* XLogPageReadCB) (XLogReaderState *xlogreader, XLogRecPtr targetPagePtr, int reqLen, XLogRecPtr targetRecPtr, char *readBuf)

Definition at line 62 of file xlogreader.h.

◆ XLogPageReadResult

◆ XLogReaderRoutine

◆ XLogReaderState

Definition at line 59 of file xlogreader.h.

Enumeration Type Documentation

◆ XLogPageReadResult

Enumerator
XLREAD_SUCCESS 
XLREAD_FAIL 
XLREAD_WOULDBLOCK 

Definition at line 349 of file xlogreader.h.

350{
351 XLREAD_SUCCESS = 0, /* record is successfully read */
352 XLREAD_FAIL = -1, /* failed during reading a record */
353 XLREAD_WOULDBLOCK = -2, /* nonblocking mode only, no data */
XLogPageReadResult
Definition: xlogreader.h:350
@ XLREAD_WOULDBLOCK
Definition: xlogreader.h:353
@ XLREAD_SUCCESS
Definition: xlogreader.h:351
@ XLREAD_FAIL
Definition: xlogreader.h:352

Function Documentation

◆ DecodeXLogRecord()

bool DecodeXLogRecord ( XLogReaderState state,
DecodedXLogRecord decoded,
XLogRecord record,
XLogRecPtr  lsn,
char **  errormsg 
)

Definition at line 1662 of file xlogreader.c.

1667{
1668 /*
1669 * read next _size bytes from record buffer, but check for overrun first.
1670 */
1671#define COPY_HEADER_FIELD(_dst, _size) \
1672 do { \
1673 if (remaining < _size) \
1674 goto shortdata_err; \
1675 memcpy(_dst, ptr, _size); \
1676 ptr += _size; \
1677 remaining -= _size; \
1678 } while(0)
1679
1680 char *ptr;
1681 char *out;
1683 uint32 datatotal;
1684 RelFileLocator *rlocator = NULL;
1685 uint8 block_id;
1686
1687 decoded->header = *record;
1688 decoded->lsn = lsn;
1689 decoded->next = NULL;
1692 decoded->main_data = NULL;
1693 decoded->main_data_len = 0;
1694 decoded->max_block_id = -1;
1695 ptr = (char *) record;
1696 ptr += SizeOfXLogRecord;
1698
1699 /* Decode the headers */
1700 datatotal = 0;
1701 while (remaining > datatotal)
1702 {
1703 COPY_HEADER_FIELD(&block_id, sizeof(uint8));
1704
1705 if (block_id == XLR_BLOCK_ID_DATA_SHORT)
1706 {
1707 /* XLogRecordDataHeaderShort */
1708 uint8 main_data_len;
1709
1710 COPY_HEADER_FIELD(&main_data_len, sizeof(uint8));
1711
1712 decoded->main_data_len = main_data_len;
1713 datatotal += main_data_len;
1714 break; /* by convention, the main data fragment is
1715 * always last */
1716 }
1717 else if (block_id == XLR_BLOCK_ID_DATA_LONG)
1718 {
1719 /* XLogRecordDataHeaderLong */
1720 uint32 main_data_len;
1721
1722 COPY_HEADER_FIELD(&main_data_len, sizeof(uint32));
1723 decoded->main_data_len = main_data_len;
1724 datatotal += main_data_len;
1725 break; /* by convention, the main data fragment is
1726 * always last */
1727 }
1728 else if (block_id == XLR_BLOCK_ID_ORIGIN)
1729 {
1730 COPY_HEADER_FIELD(&decoded->record_origin, sizeof(RepOriginId));
1731 }
1732 else if (block_id == XLR_BLOCK_ID_TOPLEVEL_XID)
1733 {
1734 COPY_HEADER_FIELD(&decoded->toplevel_xid, sizeof(TransactionId));
1735 }
1736 else if (block_id <= XLR_MAX_BLOCK_ID)
1737 {
1738 /* XLogRecordBlockHeader */
1739 DecodedBkpBlock *blk;
1740 uint8 fork_flags;
1741
1742 /* mark any intervening block IDs as not in use */
1743 for (int i = decoded->max_block_id + 1; i < block_id; ++i)
1744 decoded->blocks[i].in_use = false;
1745
1746 if (block_id <= decoded->max_block_id)
1747 {
1749 "out-of-order block_id %u at %X/%X",
1750 block_id,
1751 LSN_FORMAT_ARGS(state->ReadRecPtr));
1752 goto err;
1753 }
1754 decoded->max_block_id = block_id;
1755
1756 blk = &decoded->blocks[block_id];
1757 blk->in_use = true;
1758 blk->apply_image = false;
1759
1760 COPY_HEADER_FIELD(&fork_flags, sizeof(uint8));
1761 blk->forknum = fork_flags & BKPBLOCK_FORK_MASK;
1762 blk->flags = fork_flags;
1763 blk->has_image = ((fork_flags & BKPBLOCK_HAS_IMAGE) != 0);
1764 blk->has_data = ((fork_flags & BKPBLOCK_HAS_DATA) != 0);
1765
1767
1768 COPY_HEADER_FIELD(&blk->data_len, sizeof(uint16));
1769 /* cross-check that the HAS_DATA flag is set iff data_length > 0 */
1770 if (blk->has_data && blk->data_len == 0)
1771 {
1773 "BKPBLOCK_HAS_DATA set, but no data included at %X/%X",
1774 LSN_FORMAT_ARGS(state->ReadRecPtr));
1775 goto err;
1776 }
1777 if (!blk->has_data && blk->data_len != 0)
1778 {
1780 "BKPBLOCK_HAS_DATA not set, but data length is %u at %X/%X",
1781 (unsigned int) blk->data_len,
1782 LSN_FORMAT_ARGS(state->ReadRecPtr));
1783 goto err;
1784 }
1785 datatotal += blk->data_len;
1786
1787 if (blk->has_image)
1788 {
1789 COPY_HEADER_FIELD(&blk->bimg_len, sizeof(uint16));
1790 COPY_HEADER_FIELD(&blk->hole_offset, sizeof(uint16));
1791 COPY_HEADER_FIELD(&blk->bimg_info, sizeof(uint8));
1792
1793 blk->apply_image = ((blk->bimg_info & BKPIMAGE_APPLY) != 0);
1794
1796 {
1797 if (blk->bimg_info & BKPIMAGE_HAS_HOLE)
1798 COPY_HEADER_FIELD(&blk->hole_length, sizeof(uint16));
1799 else
1800 blk->hole_length = 0;
1801 }
1802 else
1803 blk->hole_length = BLCKSZ - blk->bimg_len;
1804 datatotal += blk->bimg_len;
1805
1806 /*
1807 * cross-check that hole_offset > 0, hole_length > 0 and
1808 * bimg_len < BLCKSZ if the HAS_HOLE flag is set.
1809 */
1810 if ((blk->bimg_info & BKPIMAGE_HAS_HOLE) &&
1811 (blk->hole_offset == 0 ||
1812 blk->hole_length == 0 ||
1813 blk->bimg_len == BLCKSZ))
1814 {
1816 "BKPIMAGE_HAS_HOLE set, but hole offset %u length %u block image length %u at %X/%X",
1817 (unsigned int) blk->hole_offset,
1818 (unsigned int) blk->hole_length,
1819 (unsigned int) blk->bimg_len,
1820 LSN_FORMAT_ARGS(state->ReadRecPtr));
1821 goto err;
1822 }
1823
1824 /*
1825 * cross-check that hole_offset == 0 and hole_length == 0 if
1826 * the HAS_HOLE flag is not set.
1827 */
1828 if (!(blk->bimg_info & BKPIMAGE_HAS_HOLE) &&
1829 (blk->hole_offset != 0 || blk->hole_length != 0))
1830 {
1832 "BKPIMAGE_HAS_HOLE not set, but hole offset %u length %u at %X/%X",
1833 (unsigned int) blk->hole_offset,
1834 (unsigned int) blk->hole_length,
1835 LSN_FORMAT_ARGS(state->ReadRecPtr));
1836 goto err;
1837 }
1838
1839 /*
1840 * Cross-check that bimg_len < BLCKSZ if it is compressed.
1841 */
1842 if (BKPIMAGE_COMPRESSED(blk->bimg_info) &&
1843 blk->bimg_len == BLCKSZ)
1844 {
1846 "BKPIMAGE_COMPRESSED set, but block image length %u at %X/%X",
1847 (unsigned int) blk->bimg_len,
1848 LSN_FORMAT_ARGS(state->ReadRecPtr));
1849 goto err;
1850 }
1851
1852 /*
1853 * cross-check that bimg_len = BLCKSZ if neither HAS_HOLE is
1854 * set nor COMPRESSED().
1855 */
1856 if (!(blk->bimg_info & BKPIMAGE_HAS_HOLE) &&
1858 blk->bimg_len != BLCKSZ)
1859 {
1861 "neither BKPIMAGE_HAS_HOLE nor BKPIMAGE_COMPRESSED set, but block image length is %u at %X/%X",
1862 (unsigned int) blk->data_len,
1863 LSN_FORMAT_ARGS(state->ReadRecPtr));
1864 goto err;
1865 }
1866 }
1867 if (!(fork_flags & BKPBLOCK_SAME_REL))
1868 {
1870 rlocator = &blk->rlocator;
1871 }
1872 else
1873 {
1874 if (rlocator == NULL)
1875 {
1877 "BKPBLOCK_SAME_REL set but no previous rel at %X/%X",
1878 LSN_FORMAT_ARGS(state->ReadRecPtr));
1879 goto err;
1880 }
1881
1882 blk->rlocator = *rlocator;
1883 }
1884 COPY_HEADER_FIELD(&blk->blkno, sizeof(BlockNumber));
1885 }
1886 else
1887 {
1889 "invalid block_id %u at %X/%X",
1890 block_id, LSN_FORMAT_ARGS(state->ReadRecPtr));
1891 goto err;
1892 }
1893 }
1894
1895 if (remaining != datatotal)
1896 goto shortdata_err;
1897
1898 /*
1899 * Ok, we've parsed the fragment headers, and verified that the total
1900 * length of the payload in the fragments is equal to the amount of data
1901 * left. Copy the data of each fragment to contiguous space after the
1902 * blocks array, inserting alignment padding before the data fragments so
1903 * they can be cast to struct pointers by REDO routines.
1904 */
1905 out = ((char *) decoded) +
1906 offsetof(DecodedXLogRecord, blocks) +
1907 sizeof(decoded->blocks[0]) * (decoded->max_block_id + 1);
1908
1909 /* block data first */
1910 for (block_id = 0; block_id <= decoded->max_block_id; block_id++)
1911 {
1912 DecodedBkpBlock *blk = &decoded->blocks[block_id];
1913
1914 if (!blk->in_use)
1915 continue;
1916
1917 Assert(blk->has_image || !blk->apply_image);
1918
1919 if (blk->has_image)
1920 {
1921 /* no need to align image */
1922 blk->bkp_image = out;
1923 memcpy(out, ptr, blk->bimg_len);
1924 ptr += blk->bimg_len;
1925 out += blk->bimg_len;
1926 }
1927 if (blk->has_data)
1928 {
1929 out = (char *) MAXALIGN(out);
1930 blk->data = out;
1931 memcpy(blk->data, ptr, blk->data_len);
1932 ptr += blk->data_len;
1933 out += blk->data_len;
1934 }
1935 }
1936
1937 /* and finally, the main data */
1938 if (decoded->main_data_len > 0)
1939 {
1940 out = (char *) MAXALIGN(out);
1941 decoded->main_data = out;
1942 memcpy(decoded->main_data, ptr, decoded->main_data_len);
1943 ptr += decoded->main_data_len;
1944 out += decoded->main_data_len;
1945 }
1946
1947 /* Report the actual size we used. */
1948 decoded->size = MAXALIGN(out - (char *) decoded);
1950 decoded->size);
1951
1952 return true;
1953
1954shortdata_err:
1956 "record with invalid length at %X/%X",
1957 LSN_FORMAT_ARGS(state->ReadRecPtr));
1958err:
1959 *errormsg = state->errormsg_buf;
1960
1961 return false;
1962}
uint32 BlockNumber
Definition: block.h:31
#define InvalidBuffer
Definition: buf.h:25
#define MAXALIGN(LEN)
Definition: c.h:765
uint8_t uint8
Definition: c.h:483
#define Assert(condition)
Definition: c.h:812
uint16_t uint16
Definition: c.h:484
uint32_t uint32
Definition: c.h:485
uint32 TransactionId
Definition: c.h:606
void err(int eval, const char *fmt,...)
Definition: err.c:43
int remaining
Definition: informix.c:692
int i
Definition: isn.c:72
#define InvalidRepOriginId
Definition: origin.h:33
uint16 hole_length
Definition: xlogreader.h:140
char * bkp_image
Definition: xlogreader.h:138
Buffer prefetch_buffer
Definition: xlogreader.h:130
RelFileLocator rlocator
Definition: xlogreader.h:125
BlockNumber blkno
Definition: xlogreader.h:127
ForkNumber forknum
Definition: xlogreader.h:126
uint16 hole_offset
Definition: xlogreader.h:139
XLogRecord header
Definition: xlogreader.h:166
struct DecodedXLogRecord * next
Definition: xlogreader.h:161
TransactionId toplevel_xid
Definition: xlogreader.h:168
uint32 main_data_len
Definition: xlogreader.h:170
RepOriginId record_origin
Definition: xlogreader.h:167
DecodedBkpBlock blocks[FLEXIBLE_ARRAY_MEMBER]
Definition: xlogreader.h:172
XLogRecPtr lsn
Definition: xlogreader.h:164
uint32 xl_tot_len
Definition: xlogrecord.h:43
Definition: regguts.h:323
#define InvalidTransactionId
Definition: transam.h:31
#define LSN_FORMAT_ARGS(lsn)
Definition: xlogdefs.h:43
uint16 RepOriginId
Definition: xlogdefs.h:65
static void report_invalid_record(XLogReaderState *state, const char *fmt,...) pg_attribute_printf(2
Definition: xlogreader.c:71
#define COPY_HEADER_FIELD(_dst, _size)
size_t DecodeXLogRecordRequiredSpace(size_t xl_tot_len)
Definition: xlogreader.c:1629
#define BKPBLOCK_FORK_MASK
Definition: xlogrecord.h:195
#define BKPBLOCK_HAS_DATA
Definition: xlogrecord.h:198
#define BKPIMAGE_APPLY
Definition: xlogrecord.h:158
#define BKPIMAGE_HAS_HOLE
Definition: xlogrecord.h:157
#define XLR_BLOCK_ID_DATA_LONG
Definition: xlogrecord.h:242
#define BKPIMAGE_COMPRESSED(info)
Definition: xlogrecord.h:164
#define XLR_BLOCK_ID_TOPLEVEL_XID
Definition: xlogrecord.h:244
#define XLR_BLOCK_ID_DATA_SHORT
Definition: xlogrecord.h:241
#define XLR_MAX_BLOCK_ID
Definition: xlogrecord.h:239
#define BKPBLOCK_SAME_REL
Definition: xlogrecord.h:200
#define XLR_BLOCK_ID_ORIGIN
Definition: xlogrecord.h:243
#define SizeOfXLogRecord
Definition: xlogrecord.h:55
#define BKPBLOCK_HAS_IMAGE
Definition: xlogrecord.h:197

References DecodedBkpBlock::apply_image, Assert, DecodedBkpBlock::bimg_info, DecodedBkpBlock::bimg_len, DecodedBkpBlock::bkp_image, BKPBLOCK_FORK_MASK, BKPBLOCK_HAS_DATA, BKPBLOCK_HAS_IMAGE, BKPBLOCK_SAME_REL, BKPIMAGE_APPLY, BKPIMAGE_COMPRESSED, BKPIMAGE_HAS_HOLE, DecodedBkpBlock::blkno, DecodedXLogRecord::blocks, COPY_HEADER_FIELD, DecodedBkpBlock::data, DecodedBkpBlock::data_len, DecodeXLogRecordRequiredSpace(), err(), DecodedBkpBlock::flags, DecodedBkpBlock::forknum, DecodedBkpBlock::has_data, DecodedBkpBlock::has_image, DecodedXLogRecord::header, DecodedBkpBlock::hole_length, DecodedBkpBlock::hole_offset, i, DecodedBkpBlock::in_use, InvalidBuffer, InvalidRepOriginId, InvalidTransactionId, DecodedXLogRecord::lsn, LSN_FORMAT_ARGS, DecodedXLogRecord::main_data, DecodedXLogRecord::main_data_len, DecodedXLogRecord::max_block_id, MAXALIGN, DecodedXLogRecord::next, DecodedBkpBlock::prefetch_buffer, DecodedXLogRecord::record_origin, remaining, report_invalid_record(), DecodedBkpBlock::rlocator, DecodedXLogRecord::size, SizeOfXLogRecord, DecodedXLogRecord::toplevel_xid, XLogRecord::xl_tot_len, XLR_BLOCK_ID_DATA_LONG, XLR_BLOCK_ID_DATA_SHORT, XLR_BLOCK_ID_ORIGIN, XLR_BLOCK_ID_TOPLEVEL_XID, and XLR_MAX_BLOCK_ID.

Referenced by XLogDecodeNextRecord(), and XLogInsertRecord().

◆ DecodeXLogRecordRequiredSpace()

size_t DecodeXLogRecordRequiredSpace ( size_t  xl_tot_len)

Definition at line 1629 of file xlogreader.c.

1630{
1631 size_t size = 0;
1632
1633 /* Account for the fixed size part of the decoded record struct. */
1634 size += offsetof(DecodedXLogRecord, blocks[0]);
1635 /* Account for the flexible blocks array of maximum possible size. */
1636 size += sizeof(DecodedBkpBlock) * (XLR_MAX_BLOCK_ID + 1);
1637 /* Account for all the raw main and block data. */
1638 size += xl_tot_len;
1639 /* We might insert padding before main_data. */
1640 size += (MAXIMUM_ALIGNOF - 1);
1641 /* We might insert padding before each block's data. */
1642 size += (MAXIMUM_ALIGNOF - 1) * (XLR_MAX_BLOCK_ID + 1);
1643 /* We might insert padding at the end. */
1644 size += (MAXIMUM_ALIGNOF - 1);
1645
1646 return size;
1647}
static pg_noinline void Size size
Definition: slab.c:607

References size, and XLR_MAX_BLOCK_ID.

Referenced by DecodeXLogRecord(), InitXLogInsert(), XLogInsertRecord(), and XLogReadRecordAlloc().

◆ RestoreBlockImage()

bool RestoreBlockImage ( XLogReaderState record,
uint8  block_id,
char *  page 
)

Definition at line 2056 of file xlogreader.c.

2057{
2058 DecodedBkpBlock *bkpb;
2059 char *ptr;
2060 PGAlignedBlock tmp;
2061
2062 if (block_id > record->record->max_block_id ||
2063 !record->record->blocks[block_id].in_use)
2064 {
2065 report_invalid_record(record,
2066 "could not restore image at %X/%X with invalid block %d specified",
2067 LSN_FORMAT_ARGS(record->ReadRecPtr),
2068 block_id);
2069 return false;
2070 }
2071 if (!record->record->blocks[block_id].has_image)
2072 {
2073 report_invalid_record(record, "could not restore image at %X/%X with invalid state, block %d",
2074 LSN_FORMAT_ARGS(record->ReadRecPtr),
2075 block_id);
2076 return false;
2077 }
2078
2079 bkpb = &record->record->blocks[block_id];
2080 ptr = bkpb->bkp_image;
2081
2082 if (BKPIMAGE_COMPRESSED(bkpb->bimg_info))
2083 {
2084 /* If a backup block image is compressed, decompress it */
2085 bool decomp_success = true;
2086
2087 if ((bkpb->bimg_info & BKPIMAGE_COMPRESS_PGLZ) != 0)
2088 {
2089 if (pglz_decompress(ptr, bkpb->bimg_len, tmp.data,
2090 BLCKSZ - bkpb->hole_length, true) < 0)
2091 decomp_success = false;
2092 }
2093 else if ((bkpb->bimg_info & BKPIMAGE_COMPRESS_LZ4) != 0)
2094 {
2095#ifdef USE_LZ4
2096 if (LZ4_decompress_safe(ptr, tmp.data,
2097 bkpb->bimg_len, BLCKSZ - bkpb->hole_length) <= 0)
2098 decomp_success = false;
2099#else
2100 report_invalid_record(record, "could not restore image at %X/%X compressed with %s not supported by build, block %d",
2101 LSN_FORMAT_ARGS(record->ReadRecPtr),
2102 "LZ4",
2103 block_id);
2104 return false;
2105#endif
2106 }
2107 else if ((bkpb->bimg_info & BKPIMAGE_COMPRESS_ZSTD) != 0)
2108 {
2109#ifdef USE_ZSTD
2110 size_t decomp_result = ZSTD_decompress(tmp.data,
2111 BLCKSZ - bkpb->hole_length,
2112 ptr, bkpb->bimg_len);
2113
2114 if (ZSTD_isError(decomp_result))
2115 decomp_success = false;
2116#else
2117 report_invalid_record(record, "could not restore image at %X/%X compressed with %s not supported by build, block %d",
2118 LSN_FORMAT_ARGS(record->ReadRecPtr),
2119 "zstd",
2120 block_id);
2121 return false;
2122#endif
2123 }
2124 else
2125 {
2126 report_invalid_record(record, "could not restore image at %X/%X compressed with unknown method, block %d",
2127 LSN_FORMAT_ARGS(record->ReadRecPtr),
2128 block_id);
2129 return false;
2130 }
2131
2132 if (!decomp_success)
2133 {
2134 report_invalid_record(record, "could not decompress image at %X/%X, block %d",
2135 LSN_FORMAT_ARGS(record->ReadRecPtr),
2136 block_id);
2137 return false;
2138 }
2139
2140 ptr = tmp.data;
2141 }
2142
2143 /* generate page, taking into account hole if necessary */
2144 if (bkpb->hole_length == 0)
2145 {
2146 memcpy(page, ptr, BLCKSZ);
2147 }
2148 else
2149 {
2150 memcpy(page, ptr, bkpb->hole_offset);
2151 /* must zero-fill the hole */
2152 MemSet(page + bkpb->hole_offset, 0, bkpb->hole_length);
2153 memcpy(page + (bkpb->hole_offset + bkpb->hole_length),
2154 ptr + bkpb->hole_offset,
2155 BLCKSZ - (bkpb->hole_offset + bkpb->hole_length));
2156 }
2157
2158 return true;
2159}
#define MemSet(start, val, len)
Definition: c.h:974
int32 pglz_decompress(const char *source, int32 slen, char *dest, int32 rawsize, bool check_complete)
DecodedXLogRecord * record
Definition: xlogreader.h:236
XLogRecPtr ReadRecPtr
Definition: xlogreader.h:206
char data[BLCKSZ]
Definition: c.h:1073
#define BKPIMAGE_COMPRESS_ZSTD
Definition: xlogrecord.h:162
#define BKPIMAGE_COMPRESS_LZ4
Definition: xlogrecord.h:161
#define BKPIMAGE_COMPRESS_PGLZ
Definition: xlogrecord.h:160

References DecodedBkpBlock::bimg_info, DecodedBkpBlock::bimg_len, DecodedBkpBlock::bkp_image, BKPIMAGE_COMPRESS_LZ4, BKPIMAGE_COMPRESS_PGLZ, BKPIMAGE_COMPRESS_ZSTD, BKPIMAGE_COMPRESSED, DecodedXLogRecord::blocks, PGAlignedBlock::data, DecodedBkpBlock::has_image, DecodedBkpBlock::hole_length, DecodedBkpBlock::hole_offset, DecodedBkpBlock::in_use, LSN_FORMAT_ARGS, DecodedXLogRecord::max_block_id, MemSet, pglz_decompress(), XLogReaderState::ReadRecPtr, XLogReaderState::record, and report_invalid_record().

Referenced by GetWALBlockInfo(), verifyBackupPageConsistency(), XLogReadBufferForRedoExtended(), and XLogRecordSaveFPWs().

◆ WALRead()

bool WALRead ( XLogReaderState state,
char *  buf,
XLogRecPtr  startptr,
Size  count,
TimeLineID  tli,
WALReadError errinfo 
)

Definition at line 1503 of file xlogreader.c.

1506{
1507 char *p;
1508 XLogRecPtr recptr;
1509 Size nbytes;
1510
1511 p = buf;
1512 recptr = startptr;
1513 nbytes = count;
1514
1515 while (nbytes > 0)
1516 {
1517 uint32 startoff;
1518 int segbytes;
1519 int readbytes;
1520
1521 startoff = XLogSegmentOffset(recptr, state->segcxt.ws_segsize);
1522
1523 /*
1524 * If the data we want is not in a segment we have open, close what we
1525 * have (if anything) and open the next one, using the caller's
1526 * provided segment_open callback.
1527 */
1528 if (state->seg.ws_file < 0 ||
1529 !XLByteInSeg(recptr, state->seg.ws_segno, state->segcxt.ws_segsize) ||
1530 tli != state->seg.ws_tli)
1531 {
1532 XLogSegNo nextSegNo;
1533
1534 if (state->seg.ws_file >= 0)
1535 state->routine.segment_close(state);
1536
1537 XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
1538 state->routine.segment_open(state, nextSegNo, &tli);
1539
1540 /* This shouldn't happen -- indicates a bug in segment_open */
1541 Assert(state->seg.ws_file >= 0);
1542
1543 /* Update the current segment info. */
1544 state->seg.ws_tli = tli;
1545 state->seg.ws_segno = nextSegNo;
1546 }
1547
1548 /* How many bytes are within this segment? */
1549 if (nbytes > (state->segcxt.ws_segsize - startoff))
1550 segbytes = state->segcxt.ws_segsize - startoff;
1551 else
1552 segbytes = nbytes;
1553
1554#ifndef FRONTEND
1555 pgstat_report_wait_start(WAIT_EVENT_WAL_READ);
1556#endif
1557
1558 /* Reset errno first; eases reporting non-errno-affecting errors */
1559 errno = 0;
1560 readbytes = pg_pread(state->seg.ws_file, p, segbytes, (off_t) startoff);
1561
1562#ifndef FRONTEND
1564#endif
1565
1566 if (readbytes <= 0)
1567 {
1568 errinfo->wre_errno = errno;
1569 errinfo->wre_req = segbytes;
1570 errinfo->wre_read = readbytes;
1571 errinfo->wre_off = startoff;
1572 errinfo->wre_seg = state->seg;
1573 return false;
1574 }
1575
1576 /* Update state for read */
1577 recptr += readbytes;
1578 nbytes -= readbytes;
1579 p += readbytes;
1580 }
1581
1582 return true;
1583}
size_t Size
Definition: c.h:559
static char * buf
Definition: pg_test_fsync.c:72
#define pg_pread
Definition: port.h:225
WALOpenSegment wre_seg
Definition: xlogreader.h:388
static void pgstat_report_wait_start(uint32 wait_event_info)
Definition: wait_event.h:85
static void pgstat_report_wait_end(void)
Definition: wait_event.h:101
#define XLogSegmentOffset(xlogptr, wal_segsz_bytes)
#define XLByteToSeg(xlrp, logSegNo, wal_segsz_bytes)
#define XLByteInSeg(xlrp, logSegNo, wal_segsz_bytes)
uint64 XLogRecPtr
Definition: xlogdefs.h:21
uint64 XLogSegNo
Definition: xlogdefs.h:48

References Assert, buf, pg_pread, pgstat_report_wait_end(), pgstat_report_wait_start(), WALReadError::wre_errno, WALReadError::wre_off, WALReadError::wre_read, WALReadError::wre_req, WALReadError::wre_seg, XLByteInSeg, XLByteToSeg, and XLogSegmentOffset.

Referenced by logical_read_xlog_page(), read_local_xlog_page_guts(), summarizer_read_local_xlog_page(), WALDumpReadPage(), and XLogSendPhysical().

◆ XLogBeginRead()

void XLogBeginRead ( XLogReaderState state,
XLogRecPtr  RecPtr 
)

Definition at line 231 of file xlogreader.c.

232{
233 Assert(!XLogRecPtrIsInvalid(RecPtr));
234
236
237 /* Begin at the passed-in record pointer. */
238 state->EndRecPtr = RecPtr;
239 state->NextRecPtr = RecPtr;
240 state->ReadRecPtr = InvalidXLogRecPtr;
241 state->DecodeRecPtr = InvalidXLogRecPtr;
242}
#define XLogRecPtrIsInvalid(r)
Definition: xlogdefs.h:29
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28
static void ResetDecoder(XLogReaderState *state)
Definition: xlogreader.c:1595

References Assert, InvalidXLogRecPtr, ResetDecoder(), and XLogRecPtrIsInvalid.

Referenced by DecodingContextFindStartpoint(), extractPageMap(), findLastCheckpoint(), LogicalReplicationSlotHasPendingWal(), LogicalSlotAdvanceAndCheckSnapState(), pg_logical_slot_get_changes_guts(), readOneRecord(), StartLogicalReplication(), SummarizeWAL(), XLogFindNextRecord(), XLogPrefetcherBeginRead(), and XlogReadTwoPhaseData().

◆ XLogFindNextRecord()

XLogRecPtr XLogFindNextRecord ( XLogReaderState state,
XLogRecPtr  RecPtr 
)

Definition at line 1383 of file xlogreader.c.

1384{
1385 XLogRecPtr tmpRecPtr;
1387 XLogPageHeader header;
1388 char *errormsg;
1389
1390 Assert(!XLogRecPtrIsInvalid(RecPtr));
1391
1392 /* Make sure ReadPageInternal() can't return XLREAD_WOULDBLOCK. */
1393 state->nonblocking = false;
1394
1395 /*
1396 * skip over potential continuation data, keeping in mind that it may span
1397 * multiple pages
1398 */
1399 tmpRecPtr = RecPtr;
1400 while (true)
1401 {
1402 XLogRecPtr targetPagePtr;
1403 int targetRecOff;
1404 uint32 pageHeaderSize;
1405 int readLen;
1406
1407 /*
1408 * Compute targetRecOff. It should typically be equal or greater than
1409 * short page-header since a valid record can't start anywhere before
1410 * that, except when caller has explicitly specified the offset that
1411 * falls somewhere there or when we are skipping multi-page
1412 * continuation record. It doesn't matter though because
1413 * ReadPageInternal() is prepared to handle that and will read at
1414 * least short page-header worth of data
1415 */
1416 targetRecOff = tmpRecPtr % XLOG_BLCKSZ;
1417
1418 /* scroll back to page boundary */
1419 targetPagePtr = tmpRecPtr - targetRecOff;
1420
1421 /* Read the page containing the record */
1422 readLen = ReadPageInternal(state, targetPagePtr, targetRecOff);
1423 if (readLen < 0)
1424 goto err;
1425
1426 header = (XLogPageHeader) state->readBuf;
1427
1428 pageHeaderSize = XLogPageHeaderSize(header);
1429
1430 /* make sure we have enough data for the page header */
1431 readLen = ReadPageInternal(state, targetPagePtr, pageHeaderSize);
1432 if (readLen < 0)
1433 goto err;
1434
1435 /* skip over potential continuation data */
1436 if (header->xlp_info & XLP_FIRST_IS_CONTRECORD)
1437 {
1438 /*
1439 * If the length of the remaining continuation data is more than
1440 * what can fit in this page, the continuation record crosses over
1441 * this page. Read the next page and try again. xlp_rem_len in the
1442 * next page header will contain the remaining length of the
1443 * continuation data
1444 *
1445 * Note that record headers are MAXALIGN'ed
1446 */
1447 if (MAXALIGN(header->xlp_rem_len) >= (XLOG_BLCKSZ - pageHeaderSize))
1448 tmpRecPtr = targetPagePtr + XLOG_BLCKSZ;
1449 else
1450 {
1451 /*
1452 * The previous continuation record ends in this page. Set
1453 * tmpRecPtr to point to the first valid record
1454 */
1455 tmpRecPtr = targetPagePtr + pageHeaderSize
1456 + MAXALIGN(header->xlp_rem_len);
1457 break;
1458 }
1459 }
1460 else
1461 {
1462 tmpRecPtr = targetPagePtr + pageHeaderSize;
1463 break;
1464 }
1465 }
1466
1467 /*
1468 * we know now that tmpRecPtr is an address pointing to a valid XLogRecord
1469 * because either we're at the first record after the beginning of a page
1470 * or we just jumped over the remaining data of a continuation.
1471 */
1472 XLogBeginRead(state, tmpRecPtr);
1473 while (XLogReadRecord(state, &errormsg) != NULL)
1474 {
1475 /* past the record we've found, break out */
1476 if (RecPtr <= state->ReadRecPtr)
1477 {
1478 /* Rewind the reader to the beginning of the last record. */
1479 found = state->ReadRecPtr;
1480 XLogBeginRead(state, found);
1481 return found;
1482 }
1483 }
1484
1485err:
1487
1488 return InvalidXLogRecPtr;
1489}
#define XLP_FIRST_IS_CONTRECORD
Definition: xlog_internal.h:74
XLogPageHeaderData * XLogPageHeader
Definition: xlog_internal.h:54
#define XLogPageHeaderSize(hdr)
Definition: xlog_internal.h:84
static int ReadPageInternal(XLogReaderState *state, XLogRecPtr pageptr, int reqLen)
Definition: xlogreader.c:1000
XLogRecord * XLogReadRecord(XLogReaderState *state, char **errormsg)
Definition: xlogreader.c:389
static void XLogReaderInvalReadState(XLogReaderState *state)
Definition: xlogreader.c:1113
void XLogBeginRead(XLogReaderState *state, XLogRecPtr RecPtr)
Definition: xlogreader.c:231
static uint32 readLen
Definition: xlogrecovery.c:233

References Assert, err(), InvalidXLogRecPtr, MAXALIGN, readLen, ReadPageInternal(), XLogBeginRead(), XLogPageHeaderSize, XLogReaderInvalReadState(), XLogReadRecord(), XLogRecPtrIsInvalid, XLP_FIRST_IS_CONTRECORD, XLogPageHeaderData::xlp_info, and XLogPageHeaderData::xlp_rem_len.

Referenced by InitXLogReaderState(), main(), and SummarizeWAL().

◆ XLogNextRecord()

DecodedXLogRecord * XLogNextRecord ( XLogReaderState state,
char **  errormsg 
)

Definition at line 325 of file xlogreader.c.

326{
327 /* Release the last record returned by XLogNextRecord(). */
329
330 if (state->decode_queue_head == NULL)
331 {
332 *errormsg = NULL;
333 if (state->errormsg_deferred)
334 {
335 if (state->errormsg_buf[0] != '\0')
336 *errormsg = state->errormsg_buf;
337 state->errormsg_deferred = false;
338 }
339
340 /*
341 * state->EndRecPtr is expected to have been set by the last call to
342 * XLogBeginRead() or XLogNextRecord(), and is the location of the
343 * error.
344 */
345 Assert(!XLogRecPtrIsInvalid(state->EndRecPtr));
346
347 return NULL;
348 }
349
350 /*
351 * Record this as the most recent record returned, so that we'll release
352 * it next time. This also exposes it to the traditional
353 * XLogRecXXX(xlogreader) macros, which work with the decoder rather than
354 * the record for historical reasons.
355 */
356 state->record = state->decode_queue_head;
357
358 /*
359 * Update the pointers to the beginning and one-past-the-end of this
360 * record, again for the benefit of historical code that expected the
361 * decoder to track this rather than accessing these fields of the record
362 * itself.
363 */
364 state->ReadRecPtr = state->record->lsn;
365 state->EndRecPtr = state->record->next_lsn;
366
367 *errormsg = NULL;
368
369 return state->record;
370}
XLogRecPtr XLogReleasePreviousRecord(XLogReaderState *state)
Definition: xlogreader.c:249

References Assert, XLogRecPtrIsInvalid, and XLogReleasePreviousRecord().

Referenced by XLogPrefetcherReadRecord(), and XLogReadRecord().

◆ XLogReadAhead()

DecodedXLogRecord * XLogReadAhead ( XLogReaderState state,
bool  nonblocking 
)

Definition at line 966 of file xlogreader.c.

967{
968 XLogPageReadResult result;
969
970 if (state->errormsg_deferred)
971 return NULL;
972
973 result = XLogDecodeNextRecord(state, nonblocking);
974 if (result == XLREAD_SUCCESS)
975 {
976 Assert(state->decode_queue_tail != NULL);
977 return state->decode_queue_tail;
978 }
979
980 return NULL;
981}
static XLogPageReadResult XLogDecodeNextRecord(XLogReaderState *state, bool nonblocking)
Definition: xlogreader.c:528

References Assert, XLogDecodeNextRecord(), and XLREAD_SUCCESS.

Referenced by XLogPrefetcherNextBlock(), and XLogReadRecord().

◆ XLogReaderAllocate()

XLogReaderState * XLogReaderAllocate ( int  wal_segment_size,
const char *  waldir,
XLogReaderRoutine routine,
void *  private_data 
)

Definition at line 106 of file xlogreader.c.

108{
110
114 if (!state)
115 return NULL;
116
117 /* initialize caller-provided support functions */
118 state->routine = *routine;
119
120 /*
121 * Permanently allocate readBuf. We do it this way, rather than just
122 * making a static array, for two reasons: (1) no need to waste the
123 * storage in most instantiations of the backend; (2) a static char array
124 * isn't guaranteed to have any particular alignment, whereas
125 * palloc_extended() will provide MAXALIGN'd storage.
126 */
127 state->readBuf = (char *) palloc_extended(XLOG_BLCKSZ,
129 if (!state->readBuf)
130 {
131 pfree(state);
132 return NULL;
133 }
134
135 /* Initialize segment info. */
137 waldir);
138
139 /* system_identifier initialized to zeroes above */
140 state->private_data = private_data;
141 /* ReadRecPtr, EndRecPtr and readLen initialized to zeroes above */
142 state->errormsg_buf = palloc_extended(MAX_ERRORMSG_LEN + 1,
144 if (!state->errormsg_buf)
145 {
146 pfree(state->readBuf);
147 pfree(state);
148 return NULL;
149 }
150 state->errormsg_buf[0] = '\0';
151
152 /*
153 * Allocate an initial readRecordBuf of minimal size, which can later be
154 * enlarged if necessary.
155 */
157 return state;
158}
#define MCXT_ALLOC_ZERO
Definition: fe_memutils.h:30
#define MCXT_ALLOC_NO_OOM
Definition: fe_memutils.h:29
void pfree(void *pointer)
Definition: mcxt.c:1521
void * palloc_extended(Size size, int flags)
Definition: mcxt.c:1368
int wal_segment_size
Definition: xlog.c:143
static void WALOpenSegmentInit(WALOpenSegment *seg, WALSegmentContext *segcxt, int segsize, const char *waldir)
Definition: xlogreader.c:207
static void static void allocate_recordbuf(XLogReaderState *state, uint32 reclength)
Definition: xlogreader.c:190
#define MAX_ERRORMSG_LEN
Definition: xlogreader.c:58

References allocate_recordbuf(), MAX_ERRORMSG_LEN, MCXT_ALLOC_NO_OOM, MCXT_ALLOC_ZERO, palloc_extended(), pfree(), wal_segment_size, and WALOpenSegmentInit().

Referenced by extractPageMap(), findLastCheckpoint(), InitWalRecovery(), InitXLogReaderState(), main(), readOneRecord(), StartReplication(), StartupDecodingContext(), SummarizeWAL(), XLogInsertRecord(), and XlogReadTwoPhaseData().

◆ XLogReaderFree()

void XLogReaderFree ( XLogReaderState state)

Definition at line 161 of file xlogreader.c.

162{
163 if (state->seg.ws_file != -1)
164 state->routine.segment_close(state);
165
166 if (state->decode_buffer && state->free_decode_buffer)
167 pfree(state->decode_buffer);
168
169 pfree(state->errormsg_buf);
170 if (state->readRecordBuf)
171 pfree(state->readRecordBuf);
172 pfree(state->readBuf);
173 pfree(state);
174}

References pfree().

Referenced by extractPageMap(), findLastCheckpoint(), FreeDecodingContext(), GetWALRecordsInfo(), main(), pg_get_wal_block_info(), pg_get_wal_record_info(), readOneRecord(), ShutdownWalRecovery(), SummarizeWAL(), and XlogReadTwoPhaseData().

◆ XLogReaderHasQueuedRecordOrError()

static bool XLogReaderHasQueuedRecordOrError ( XLogReaderState state)
inlinestatic

Definition at line 325 of file xlogreader.h.

326{
327 return (state->decode_queue_head != NULL) || state->errormsg_deferred;
328}

Referenced by XLogPrefetcherNextBlock(), XLogPrefetcherReadRecord(), and XLogReadRecord().

◆ XLogReaderResetError()

void XLogReaderResetError ( XLogReaderState state)

Definition at line 1365 of file xlogreader.c.

1366{
1367 state->errormsg_buf[0] = '\0';
1368 state->errormsg_deferred = false;
1369}

Referenced by XLogPageRead().

◆ XLogReaderSetDecodeBuffer()

void XLogReaderSetDecodeBuffer ( XLogReaderState state,
void *  buffer,
size_t  size 
)

Definition at line 90 of file xlogreader.c.

91{
92 Assert(state->decode_buffer == NULL);
93
94 state->decode_buffer = buffer;
95 state->decode_buffer_size = size;
96 state->decode_buffer_tail = buffer;
97 state->decode_buffer_head = buffer;
98}

References Assert, and size.

Referenced by InitWalRecovery().

◆ XLogReaderValidatePageHeader()

bool XLogReaderValidatePageHeader ( XLogReaderState state,
XLogRecPtr  recptr,
char *  phdr 
)

Definition at line 1224 of file xlogreader.c.

1226{
1227 XLogSegNo segno;
1228 int32 offset;
1229 XLogPageHeader hdr = (XLogPageHeader) phdr;
1230
1231 Assert((recptr % XLOG_BLCKSZ) == 0);
1232
1233 XLByteToSeg(recptr, segno, state->segcxt.ws_segsize);
1234 offset = XLogSegmentOffset(recptr, state->segcxt.ws_segsize);
1235
1236 if (hdr->xlp_magic != XLOG_PAGE_MAGIC)
1237 {
1238 char fname[MAXFNAMELEN];
1239
1240 XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
1241
1243 "invalid magic number %04X in WAL segment %s, LSN %X/%X, offset %u",
1244 hdr->xlp_magic,
1245 fname,
1246 LSN_FORMAT_ARGS(recptr),
1247 offset);
1248 return false;
1249 }
1250
1251 if ((hdr->xlp_info & ~XLP_ALL_FLAGS) != 0)
1252 {
1253 char fname[MAXFNAMELEN];
1254
1255 XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
1256
1258 "invalid info bits %04X in WAL segment %s, LSN %X/%X, offset %u",
1259 hdr->xlp_info,
1260 fname,
1261 LSN_FORMAT_ARGS(recptr),
1262 offset);
1263 return false;
1264 }
1265
1266 if (hdr->xlp_info & XLP_LONG_HEADER)
1267 {
1268 XLogLongPageHeader longhdr = (XLogLongPageHeader) hdr;
1269
1270 if (state->system_identifier &&
1271 longhdr->xlp_sysid != state->system_identifier)
1272 {
1274 "WAL file is from different database system: WAL file database system identifier is %llu, pg_control database system identifier is %llu",
1275 (unsigned long long) longhdr->xlp_sysid,
1276 (unsigned long long) state->system_identifier);
1277 return false;
1278 }
1279 else if (longhdr->xlp_seg_size != state->segcxt.ws_segsize)
1280 {
1282 "WAL file is from different database system: incorrect segment size in page header");
1283 return false;
1284 }
1285 else if (longhdr->xlp_xlog_blcksz != XLOG_BLCKSZ)
1286 {
1288 "WAL file is from different database system: incorrect XLOG_BLCKSZ in page header");
1289 return false;
1290 }
1291 }
1292 else if (offset == 0)
1293 {
1294 char fname[MAXFNAMELEN];
1295
1296 XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
1297
1298 /* hmm, first page of file doesn't have a long header? */
1300 "invalid info bits %04X in WAL segment %s, LSN %X/%X, offset %u",
1301 hdr->xlp_info,
1302 fname,
1303 LSN_FORMAT_ARGS(recptr),
1304 offset);
1305 return false;
1306 }
1307
1308 /*
1309 * Check that the address on the page agrees with what we expected. This
1310 * check typically fails when an old WAL segment is recycled, and hasn't
1311 * yet been overwritten with new data yet.
1312 */
1313 if (hdr->xlp_pageaddr != recptr)
1314 {
1315 char fname[MAXFNAMELEN];
1316
1317 XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
1318
1320 "unexpected pageaddr %X/%X in WAL segment %s, LSN %X/%X, offset %u",
1322 fname,
1323 LSN_FORMAT_ARGS(recptr),
1324 offset);
1325 return false;
1326 }
1327
1328 /*
1329 * Since child timelines are always assigned a TLI greater than their
1330 * immediate parent's TLI, we should never see TLI go backwards across
1331 * successive pages of a consistent WAL sequence.
1332 *
1333 * Sometimes we re-read a segment that's already been (partially) read. So
1334 * we only verify TLIs for pages that are later than the last remembered
1335 * LSN.
1336 */
1337 if (recptr > state->latestPagePtr)
1338 {
1339 if (hdr->xlp_tli < state->latestPageTLI)
1340 {
1341 char fname[MAXFNAMELEN];
1342
1343 XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
1344
1346 "out-of-sequence timeline ID %u (after %u) in WAL segment %s, LSN %X/%X, offset %u",
1347 hdr->xlp_tli,
1348 state->latestPageTLI,
1349 fname,
1350 LSN_FORMAT_ARGS(recptr),
1351 offset);
1352 return false;
1353 }
1354 }
1355 state->latestPagePtr = recptr;
1356 state->latestPageTLI = hdr->xlp_tli;
1357
1358 return true;
1359}
int32_t int32
Definition: c.h:481
TimeLineID xlp_tli
Definition: xlog_internal.h:40
XLogRecPtr xlp_pageaddr
Definition: xlog_internal.h:41
XLogLongPageHeaderData * XLogLongPageHeader
Definition: xlog_internal.h:71
#define MAXFNAMELEN
#define XLP_LONG_HEADER
Definition: xlog_internal.h:76
#define XLP_ALL_FLAGS
Definition: xlog_internal.h:82
#define XLOG_PAGE_MAGIC
Definition: xlog_internal.h:34
static void XLogFileName(char *fname, TimeLineID tli, XLogSegNo logSegNo, int wal_segsz_bytes)

References Assert, LSN_FORMAT_ARGS, MAXFNAMELEN, report_invalid_record(), XLByteToSeg, XLOG_PAGE_MAGIC, XLogFileName(), XLogSegmentOffset, XLP_ALL_FLAGS, XLogPageHeaderData::xlp_info, XLP_LONG_HEADER, XLogPageHeaderData::xlp_magic, XLogPageHeaderData::xlp_pageaddr, XLogLongPageHeaderData::xlp_seg_size, XLogLongPageHeaderData::xlp_sysid, XLogPageHeaderData::xlp_tli, and XLogLongPageHeaderData::xlp_xlog_blcksz.

Referenced by ReadPageInternal(), and XLogPageRead().

◆ XLogReadRecord()

struct XLogRecord * XLogReadRecord ( XLogReaderState state,
char **  errormsg 
)

Definition at line 389 of file xlogreader.c.

390{
391 DecodedXLogRecord *decoded;
392
393 /*
394 * Release last returned record, if there is one. We need to do this so
395 * that we can check for empty decode queue accurately.
396 */
398
399 /*
400 * Call XLogReadAhead() in blocking mode to make sure there is something
401 * in the queue, though we don't use the result.
402 */
404 XLogReadAhead(state, false /* nonblocking */ );
405
406 /* Consume the head record or error. */
407 decoded = XLogNextRecord(state, errormsg);
408 if (decoded)
409 {
410 /*
411 * This function returns a pointer to the record's header, not the
412 * actual decoded record. The caller will access the decoded record
413 * through the XLogRecGetXXX() macros, which reach the decoded
414 * recorded as xlogreader->record.
415 */
416 Assert(state->record == decoded);
417 return &decoded->header;
418 }
419
420 return NULL;
421}
DecodedXLogRecord * XLogReadAhead(XLogReaderState *state, bool nonblocking)
Definition: xlogreader.c:966
DecodedXLogRecord * XLogNextRecord(XLogReaderState *state, char **errormsg)
Definition: xlogreader.c:325
static bool XLogReaderHasQueuedRecordOrError(XLogReaderState *state)
Definition: xlogreader.h:325

References Assert, DecodedXLogRecord::header, XLogNextRecord(), XLogReadAhead(), XLogReaderHasQueuedRecordOrError(), and XLogReleasePreviousRecord().

Referenced by DecodingContextFindStartpoint(), extractPageMap(), findLastCheckpoint(), LogicalReplicationSlotHasPendingWal(), LogicalSlotAdvanceAndCheckSnapState(), main(), pg_logical_slot_get_changes_guts(), ReadNextXLogRecord(), readOneRecord(), SummarizeWAL(), XLogFindNextRecord(), XlogReadTwoPhaseData(), and XLogSendLogical().

◆ XLogRecGetBlockData()

char * XLogRecGetBlockData ( XLogReaderState record,
uint8  block_id,
Size len 
)

◆ XLogRecGetBlockTag()

void XLogRecGetBlockTag ( XLogReaderState record,
uint8  block_id,
RelFileLocator rlocator,
ForkNumber forknum,
BlockNumber blknum 
)

Definition at line 1971 of file xlogreader.c.

1974{
1975 if (!XLogRecGetBlockTagExtended(record, block_id, rlocator, forknum,
1976 blknum, NULL))
1977 {
1978#ifndef FRONTEND
1979 elog(ERROR, "could not locate backup block with ID %d in WAL record",
1980 block_id);
1981#else
1982 pg_fatal("could not locate backup block with ID %d in WAL record",
1983 block_id);
1984#endif
1985 }
1986}
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:225
#define pg_fatal(...)
bool XLogRecGetBlockTagExtended(XLogReaderState *record, uint8 block_id, RelFileLocator *rlocator, ForkNumber *forknum, BlockNumber *blknum, Buffer *prefetch_buffer)
Definition: xlogreader.c:1997

References elog, ERROR, pg_fatal, and XLogRecGetBlockTagExtended().

Referenced by brin_xlog_revmap_extend(), btree_xlog_delete(), btree_xlog_split(), DecodeDelete(), DecodeInsert(), DecodeMultiInsert(), DecodeSpecConfirm(), DecodeUpdate(), gistRedoDeleteRecord(), gistRedoPageSplitRecord(), hash_xlog_add_ovfl_page(), hash_xlog_init_bitmap_page(), hash_xlog_init_meta_page(), hash_xlog_vacuum_one_page(), heap_xlog_delete(), heap_xlog_insert(), heap_xlog_lock(), heap_xlog_lock_updated(), heap_xlog_multi_insert(), heap_xlog_prune_freeze(), heap_xlog_update(), heap_xlog_visible(), spgRedoAddLeaf(), spgRedoAddNode(), spgRedoMoveLeafs(), spgRedoPickSplit(), and spgRedoVacuumRedirect().

◆ XLogRecGetBlockTagExtended()

bool XLogRecGetBlockTagExtended ( XLogReaderState record,
uint8  block_id,
RelFileLocator rlocator,
ForkNumber forknum,
BlockNumber blknum,
Buffer prefetch_buffer 
)

Definition at line 1997 of file xlogreader.c.

2001{
2002 DecodedBkpBlock *bkpb;
2003
2004 if (!XLogRecHasBlockRef(record, block_id))
2005 return false;
2006
2007 bkpb = &record->record->blocks[block_id];
2008 if (rlocator)
2009 *rlocator = bkpb->rlocator;
2010 if (forknum)
2011 *forknum = bkpb->forknum;
2012 if (blknum)
2013 *blknum = bkpb->blkno;
2014 if (prefetch_buffer)
2015 *prefetch_buffer = bkpb->prefetch_buffer;
2016 return true;
2017}
#define XLogRecHasBlockRef(decoder, block_id)
Definition: xlogreader.h:420

References DecodedBkpBlock::blkno, DecodedXLogRecord::blocks, DecodedBkpBlock::forknum, DecodedBkpBlock::prefetch_buffer, XLogReaderState::record, DecodedBkpBlock::rlocator, and XLogRecHasBlockRef.

Referenced by btree_xlog_split(), extractPageInfo(), GetWALBlockInfo(), heap_xlog_update(), SummarizeWAL(), verifyBackupPageConsistency(), xlog_block_info(), XLogReadBufferForRedoExtended(), XLogRecGetBlockRefInfo(), XLogRecGetBlockTag(), XLogRecordMatchesRelationBlock(), and XLogRecordSaveFPWs().

◆ XLogRecGetFullXid()

FullTransactionId XLogRecGetFullXid ( XLogReaderState record)

Definition at line 2167 of file xlogreader.c.

2168{
2169 TransactionId xid,
2170 next_xid;
2171 uint32 epoch;
2172
2173 /*
2174 * This function is only safe during replay, because it depends on the
2175 * replay state. See AdvanceNextFullTransactionIdPastXid() for more.
2176 */
2178
2179 xid = XLogRecGetXid(record);
2182
2183 /*
2184 * If xid is numerically greater than next_xid, it has to be from the last
2185 * epoch.
2186 */
2187 if (unlikely(xid > next_xid))
2188 --epoch;
2189
2191}
#define unlikely(x)
Definition: c.h:330
bool IsUnderPostmaster
Definition: globals.c:119
#define AmStartupProcess()
Definition: miscadmin.h:388
FullTransactionId nextXid
Definition: transam.h:220
#define EpochFromFullTransactionId(x)
Definition: transam.h:47
#define XidFromFullTransactionId(x)
Definition: transam.h:48
static FullTransactionId FullTransactionIdFromEpochAndXid(uint32 epoch, TransactionId xid)
Definition: transam.h:71
TransamVariablesData * TransamVariables
Definition: varsup.c:34
static const unsigned __int64 epoch
#define XLogRecGetXid(decoder)
Definition: xlogreader.h:412

References AmStartupProcess, Assert, epoch, EpochFromFullTransactionId, FullTransactionIdFromEpochAndXid(), IsUnderPostmaster, TransamVariablesData::nextXid, TransamVariables, unlikely, XidFromFullTransactionId, and XLogRecGetXid.

◆ XLogReleasePreviousRecord()

XLogRecPtr XLogReleasePreviousRecord ( XLogReaderState state)

Definition at line 249 of file xlogreader.c.

250{
251 DecodedXLogRecord *record;
252 XLogRecPtr next_lsn;
253
254 if (!state->record)
255 return InvalidXLogRecPtr;
256
257 /*
258 * Remove it from the decoded record queue. It must be the oldest item
259 * decoded, decode_queue_head.
260 */
261 record = state->record;
262 next_lsn = record->next_lsn;
263 Assert(record == state->decode_queue_head);
264 state->record = NULL;
265 state->decode_queue_head = record->next;
266
267 /* It might also be the newest item decoded, decode_queue_tail. */
268 if (state->decode_queue_tail == record)
269 state->decode_queue_tail = NULL;
270
271 /* Release the space. */
272 if (unlikely(record->oversized))
273 {
274 /* It's not in the decode buffer, so free it to release space. */
275 pfree(record);
276 }
277 else
278 {
279 /* It must be the head (oldest) record in the decode buffer. */
280 Assert(state->decode_buffer_head == (char *) record);
281
282 /*
283 * We need to update head to point to the next record that is in the
284 * decode buffer, if any, being careful to skip oversized ones
285 * (they're not in the decode buffer).
286 */
287 record = record->next;
288 while (unlikely(record && record->oversized))
289 record = record->next;
290
291 if (record)
292 {
293 /* Adjust head to release space up to the next record. */
294 state->decode_buffer_head = (char *) record;
295 }
296 else
297 {
298 /*
299 * Otherwise we might as well just reset head and tail to the
300 * start of the buffer space, because we're empty. This means
301 * we'll keep overwriting the same piece of memory if we're not
302 * doing any prefetching.
303 */
304 state->decode_buffer_head = state->decode_buffer;
305 state->decode_buffer_tail = state->decode_buffer;
306 }
307 }
308
309 return next_lsn;
310}
XLogRecPtr next_lsn
Definition: xlogreader.h:165

References Assert, InvalidXLogRecPtr, DecodedXLogRecord::next, DecodedXLogRecord::next_lsn, DecodedXLogRecord::oversized, pfree(), and unlikely.

Referenced by XLogNextRecord(), XLogPrefetcherReadRecord(), and XLogReadRecord().