-C Change\sthe\sinterface\sto\sinternal\sfunction\swalGetHash()\sto\smake\sit\seasier\sto\sfollow.
-D 2010-06-14T11:18:51
+C Update\ssome\scomments\sin\swal.c.\sNo\scode\schanges.
+D 2010-06-14T11:49:26
F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
F Makefile.in a5cad1f8f3e021356bfcc6c77dc16f6f1952bbc3
F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
F src/vdbemem.c 2a82f455f6ca6f78b59fb312f96054c04ae0ead1
F src/vdbetrace.c 864cef96919323482ebd9986f2132435115e9cc2
F src/vtab.c a0f8a40274e4261696ef57aa806de2776ab72cda
-F src/wal.c eb0a433af578bccd8c3742806d8f2748976aa894
+F src/wal.c f8ba403da99ed5f2260f03cd01c3f10fe8155e67
F src/wal.h 4ace25262452d17e7d3ec970c89ee17794004008
F src/walker.c 3112bb3afe1d85dc52317cb1d752055e9a781f8f
F src/where.c 1c895bef33d0dfc7ed90fb1f74120435d210ea56
F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 1008f536440840da7d56c01ec147a25295fd1fd4
-R 912042aef26c7174a859c811eae607e9
+P 5e8e2e978ea48ce4ad93a936c838934f33d665df
+R 4612706a9d4bf144a165ca75ff4d4a89
U dan
-Z 1a6bfab282147a6b78cbcbccc32bce51
+Z d61a90eb1d7a0bbf02b4e4817b07d279
** more index blocks.
**
** The wal-index header contains the total number of frames within the WAL
-** in the the mxFrame field. Each index block contains information on
-** HASHTABLE_NPAGE frames. Each index block contains two sections, a
-** mapping which is a database page number for each frame, and a hash
-** table used to look up frames by page number. The mapping section is
-** an array of HASHTABLE_NPAGE 32-bit page numbers. The first entry on the
-** array is the page number for the first frame; the second entry is the
-** page number for the second frame; and so forth. The last index block
-** holds a total of (mxFrame%HASHTABLE_NPAGE) page numbers. All index
-** blocks other than the last are completely full with HASHTABLE_NPAGE
-** page numbers. All index blocks are the same size; the mapping section
-** of the last index block merely contains unused entries if mxFrame is
-** not an even multiple of HASHTABLE_NPAGE.
+** in the the mxFrame field.
+**
+** Each index block except for the first contains information on
+** HASHTABLE_NPAGE frames. The first index block contains information on
+** HASHTABLE_NPAGE_ONE frames. The values of HASHTABLE_NPAGE_ONE and
+** HASHTABLE_NPAGE are selected so that together the wal-index header and
+** first index block are the same size as all other index blocks in the
+** wal-index.
+**
+** Each index block contains two sections, a page-mapping that contains the
+** database page number associated with each wal frame, and a hash-table
+** that allows users to query an index block for a specific page number.
+** The page-mapping is an array of HASHTABLE_NPAGE (or HASHTABLE_NPAGE_ONE
+** for the first index block) 32-bit page numbers. The first entry in the
+** first index-block contains the database page number corresponding to the
+** first frame in the WAL file. The first entry in the second index block
+** in the WAL file corresponds to the (HASHTABLE_NPAGE_ONE+1)th frame in
+** the log, and so on.
+**
+** The last index block in a wal-index usually contains less than the full
+** complement of HASHTABLE_NPAGE (or HASHTABLE_NPAGE_ONE) page-numbers,
+** depending on the contents of the WAL file. This does not change the
+** allocated size of the page-mapping array - the page-mapping array merely
+** contains unused entries.
**
** Even without using the hash table, the last frame for page P
-** can be found by scanning the mapping sections of each index block
+** can be found by scanning the page-mapping sections of each index block
** starting with the last index block and moving toward the first, and
** within each index block, starting at the end and moving toward the
** beginning. The first entry that equals P corresponds to the frame
*/
typedef u16 ht_slot;
+/*
+** This structure is used to implement an iterator that loops through
+** all frames in the WAL in database page order. Where two or more frames
+** correspond to the same database page, the iterator visits only the
+** frame most recently written to the WAL (in other words, the frame with
+** the largest index).
+**
+** The internals of this structure are only accessed by:
+**
+** walIteratorInit() - Create a new iterator,
+** walIteratorNext() - Step an iterator,
+** walIteratorFree() - Free an iterator.
+**
+** This functionality is used by the checkpoint code (see walCheckpoint()).
+*/
+struct WalIterator {
+ int iPrior; /* Last result returned from the iterator */
+ int nSegment; /* Size of the aSegment[] array */
+ struct WalSegment {
+ int iNext; /* Next slot in aIndex[] not yet returned */
+ ht_slot *aIndex; /* i0, i1, i2... such that aPgno[iN] ascend */
+ u32 *aPgno; /* Array of page numbers. */
+ int nEntry; /* Max size of aPgno[] and aIndex[] arrays */
+ int iZero; /* Frame number associated with aPgno[0] */
+ } aSegment[1]; /* One for every 32KB page in the WAL */
+};
+
/*
** Define the parameters of the hash tables in the wal-index file. There
** is a hash-table following every HASHTABLE_NPAGE page numbers in the
#define HASHTABLE_HASH_1 383 /* Should be prime */
#define HASHTABLE_NSLOT (HASHTABLE_NPAGE*2) /* Must be a power of 2 */
-/* The block of page numbers associated with the first hash-table in a
+/*
+** The block of page numbers associated with the first hash-table in a
** wal-index is smaller than usual. This is so that there is a complete
** hash-table on each aligned 32KB page of the wal-index.
*/
return (volatile WalIndexHdr*)pWal->apWiData[0];
}
-/*
-** This structure is used to implement an iterator that loops through
-** all frames in the WAL in database page order. Where two or more frames
-** correspond to the same database page, the iterator visits only the
-** frame most recently written to the WAL (in other words, the frame with
-** the largest index).
-**
-** The internals of this structure are only accessed by:
-**
-** walIteratorInit() - Create a new iterator,
-** walIteratorNext() - Step an iterator,
-** walIteratorFree() - Free an iterator.
-**
-** This functionality is used by the checkpoint code (see walCheckpoint()).
-*/
-struct WalIterator {
- int iPrior; /* Last result returned from the iterator */
- int nSegment; /* Size of the aSegment[] array */
- struct WalSegment {
- int iNext; /* Next slot in aIndex[] not yet returned */
- ht_slot *aIndex; /* i0, i1, i2... such that aPgno[iN] ascend */
- u32 *aPgno; /* Array of page numbers. */
- int nEntry; /* Max size of aPgno[] and aIndex[] arrays */
- int iZero; /* Frame number associated with aPgno[0] */
- } aSegment[1]; /* One for every 32KB page in the WAL */
-};
-
/*
** The argument to this macro must be of type u32. On a little-endian
** architecture, it returns the u32 value that results from interpreting
projects / thirdparty / sqlite.git / commitdiff
