open-source-search-engine/OldDiskPageCache.cpp
Matt a1ed368d82 bring back max mem control into master controls.
it's useful to limit per process mem usage to prevent
oom killer because we can't save if we get killed.
overhaul diskpagecache to just use rdbcache. much simpler
and faster, but disabled for now until debugged more.
reduce min files to merge for crawlbot collections so
they stay more tightly merged to conserve fds and mem.
improved logDebugDisk msgs.
overhauled File.cpp fd pool. now it is way faster and
doesn't use any extra mem. much simpler too. although
could be sped up a little by using a linked list, but
probably is not significant enough to warrant doing right now.
increase mem ptr table from 3M to 8M slots. should really make
dynamic though. fix core from null msg20s[0]->m_r.
only call attemptMergeAll once every 60 seconds really.
do not attempt merge if already merging.
2015-08-14 12:58:54 -06:00

1586 lines
52 KiB
C++

#undef _XOPEN_SOURCE // needed for pread and pwrite
#define _XOPEN_SOURCE 500
#include "gb-include.h"
#include "DiskPageCache.h"
#include "RdbMap.h" // GB_PAGE_SIZE
#include "Indexdb.h"
#include "Profiler.h"
// types.h uses key_t type that shmget uses
//#undef key_t
/*
#ifdef GBUSESHM
#include <sys/ipc.h> // shmget()
#include <sys/shm.h> // shmget()
#endif
*/
// FORMAT of a MEMORY PAGE representing a DISK PAGE
//
// HEADER:
//
// bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbb # of disk data bytes stored in this page
// ffffffff ffffffff ffffffff fffffff Offset into memory page they are stored
// pppppppp pppppppp pppppppp ppppppp Offset of prev mem page in linked list
// nnnnnnnn nnnnnnnn nnnnnnnn nnnnnnn Offset of next mem page in linked list
// dddddddd dddddddd dddddddd ddddddd Disk page # mem page is mapping.
// vvvvvvvv vvvvvvvv vvvvvvvv vvvvvvv vfd of file page is mapping
//
// DDDDDDDD ........ raw disk data at that page...
// offsets in bytes in the header each entry has.
// should total HEADERSIZE bytes.
#define OFF_SIZE 0
#define OFF_SKIP (int)(sizeof(int32_t))
#define OFF_PREV (int)(sizeof(int32_t)*2)
#define OFF_NEXT (int)(sizeof(int32_t)*3)
#define OFF_DISKPAGENUM (int)(sizeof(int32_t)*4)
#define OFF_VFD (int)(sizeof(int32_t)*5)
// store disk data iteself into page at this offset
#define HEADERSIZE (int)(sizeof(int32_t)*6)
DiskPageCache::DiskPageCache () {
m_numPageSets = 0;
// sometimes db may pass an unitialized DiskPageCache to a BigFile
// so make sure when BigFile::close calls DiskPageCache::rmVfd() our
// m_memOffFromDiskPage vector is all NULLed out, otherwise
// it will core
//memset ( m_memOff , 0 , sizeof(int32_t *) * MAX_NUM_VFDS2 );
for ( int32_t i = 0 ; i < MAX_NUM_VFDS2 ; i++ )
m_memOffFromDiskPage[i] = NULL;
m_availMemOff = NULL;
//m_isOverriden = false;
reset();
}
DiskPageCache::~DiskPageCache() {
reset();
}
/*
#ifdef GBUSESHM
static char *s_mem = NULL;
static int s_shmid = -1;
#endif
*/
void DiskPageCache::reset() {
if ( m_numPageSets > 0 )
log("db: resetting page cache for %s",m_dbname);
// . "m_pageSet[]" the actual memory buffers for holding disk pages
// . we allocate one m_pageSet[] at a time like pools
for ( int32_t i = 0 ; i < m_numPageSets ; i++ ) {
mfree ( m_pageSet[i], m_pageSetSize[i], "DiskPageCache");
m_pageSet [i] = NULL;
m_pageSetSize[i] = 0;
}
// . free all the m_memOffs[] arrays
// . free map that maps this files pages on disk to pages/offs in mem
// . m_memOffs[DISKPAGENUM] -> MEMPAGEOFFSET
for ( int32_t i = 0 ; i < MAX_NUM_VFDS2 ; i++ ) {
if ( ! m_memOffFromDiskPage [ i ] ) continue;
int32_t size = m_maxPagesInFile[i] * sizeof(int32_t);
mfree ( m_memOffFromDiskPage [ i ] , size , "DiskPageCache" );
m_memOffFromDiskPage [ i ] = NULL;
}
// . and these contain offsets to available memory pages
// . there are m_numAvailMemOffs of them
// . m_availMemOff[0] would map to the memory offset of the next
// available memory page. kinda like m_memOffFromDiskPage[] but that one is
// for used pages
if ( m_availMemOff ) {
int32_t size = m_maxAvailMemOffs * sizeof(int32_t);
mfree ( m_availMemOff , size , "DiskPageCache" );
}
/*
#ifdef GBUSESHM
// free current one, if exists
if ( s_shmid >= 0 && s_mem ) {
if ( shmdt ( s_mem ) == -1 )
log("disk: shmdt: reset: %s",mstrerror(errno));
s_mem = NULL;
s_shmid = -1;
}
// mark shared mem for destruction
for ( int32_t i = 0 ; m_useSHM && i < m_numShmids ; i++ ) {
int shmid = m_shmids[i];
if ( shmctl ( shmid , IPC_RMID , NULL) == -1 )
log("db: shmctlt shmid=%"INT32": %s",
(int32_t)shmid,mstrerror(errno));
else
log("db: shmctl freed shmid=%"INT32"",(int32_t)shmid);
}
#endif
*/
m_numPageSets = 0;
m_nextMemOff = 0;
m_upperMemOff = 0;
m_maxMem = 0;
m_memAlloced = 0;
m_availMemOff = NULL;
m_numAvailMemOffs = 0;
m_maxAvailMemOffs = 0;
m_headOff = -1;
m_tailOff = -1;
m_enabled = true;
m_nexti = 0;
//m_ramfd = -1;
//m_useRAMDisk = false;
//m_useSHM = false;
}
bool DiskPageCache::init ( const char *dbname ,
char rdbId,
int32_t maxMem ,
int32_t pageSize,
bool useRAMDisk,
bool minimizeDiskSeeks ) {
// int32_t maxMem ,
// void (*getPages2)(DiskPageCache*, int32_t, char*,
// int32_t, int64_t, int32_t*,
// int64_t*),
// void (*addPages2)(DiskPageCache*, int32_t, char*,
// int32_t, int64_t),
// int32_t (*getVfd2)(DiskPageCache*, int64_t),
// void (*rmVfd2)(DiskPageCache*, int32_t) ) {
reset();
// seems like we lose data when it prints "Caught add breach"
// so let's stop using until we fix that... happens while we are
// dumping i think and somehow the data seems to get lost that
// we were dumping.
//maxMem = 0;
m_rdbId = rdbId;
bool *tog = NULL;
if (m_rdbId==RDB_INDEXDB ) tog=&g_conf.m_useDiskPageCacheIndexdb;
if (m_rdbId==RDB_POSDB ) tog=&g_conf.m_useDiskPageCachePosdb;
if (m_rdbId==RDB_DATEDB ) tog=&g_conf.m_useDiskPageCacheDatedb;
if (m_rdbId==RDB_TITLEDB ) tog=&g_conf.m_useDiskPageCacheTitledb;
if (m_rdbId==RDB_SPIDERDB ) tog=&g_conf.m_useDiskPageCacheSpiderdb;
if (m_rdbId==RDB_TFNDB ) tog=&g_conf.m_useDiskPageCacheTfndb;
if (m_rdbId==RDB_TAGDB ) tog=&g_conf.m_useDiskPageCacheTagdb;
if (m_rdbId==RDB_CLUSTERDB ) tog=&g_conf.m_useDiskPageCacheClusterdb;
if (m_rdbId==RDB_CATDB ) tog=&g_conf.m_useDiskPageCacheCatdb;
if (m_rdbId==RDB_LINKDB ) tog=&g_conf.m_useDiskPageCacheLinkdb;
m_switch = tog;
/*
bool useSHM = false;
// a quick hacky thing, force them to use shared mem instead of ram dsk
if ( useRAMDisk ) {
useRAMDisk = false;
useSHM = true;
}
*/
// not for tmp cluster
//if ( g_hostdb.m_useTmpCluster ) useSHM = false;
// it is off by default because it leaks easily (if u Ctrl+C the process)
//if ( ! g_conf.m_useSHM ) useSHM = false;
// right now shared mem only supports a single page size because
// we use s_mem/s_shmid, and if we have a small page size which
// we free, then shmat() may get ENOMEM when trying to get the larger
// of the two page sizes
//if(useSHM && pageSize != GB_INDEXDB_PAGE_SIZE) {char *xx=NULL;*xx=0;}
// don't use it until we figure out how to stop the memory from being
// counted as being the process's memory space. i think we can make
// shmat() use the same mem address each time...
// if ( useSHM ) {
// log("disk: shared mem currently not supported. Turn off "
// "in gb.conf <useSharedMem>");
// char *xx=NULL;*xx=0;
// }
// save it;
//m_useSHM = useSHM;
// clear it
//m_numShmids = 0;
// set this
//m_maxAllocSize = 33554432;
// the shared mem page size is a little more than the disk page size
//m_spageSize = pageSize + HEADERSIZE;
// . this is /proc/sys/kernel/shmmax DIVIDED BY 2 on titan and gk0 now
// . which is the max to get per call to shmat()
// . making this smaller did not seem to have much effect on speed
//int32_t max = 33554432/2;
// make sure it is "pageSize" aligned so we don't split pages
//m_maxAllocSize = (max / m_spageSize) * m_spageSize;
// max of ~16MB worth of pages
//int32_t adjPageSize = pageSize + HEADERSIZE;
//m_maxAllocSize = 2000000000; // 2GB (16000000 / adjPageSize) * adjPageSize;
/*
#ifdef GBUSESHM
// set it up
if ( m_useSHM ) {
// we can only use like 30MB shared mem pieces
int32_t need = maxMem;
shmloop:
// how much to alloc now?
int32_t alloc = need;
// this is /proc/sys/kernel/shmmax on titan and gk0 now
if ( alloc > m_maxAllocSize ) alloc = m_maxAllocSize;
// don't allow anything lower than this because we always
// "swap out" one for another below. that is, we call shmdt()
// to free it then shmat() to reclaim it. otherwise, shmat()
// will run out of memory!!
if ( alloc < m_maxAllocSize ) alloc = m_maxAllocSize;
// get it // SHM_R|SHM_W|SHM_R>>3|SHM_R>>6|...
int shmid = shmget(IPC_PRIVATE, alloc, SHM_R|SHM_W|IPC_CREAT);
// on error, bail
if ( shmid == -1 )
return log("db: shmget: %s",mstrerror(errno));
// don't swap it out (only 2.6 kernel i think)
//if ( shmctl ( shmid , SHM_LOCK , NULL ) )
// return log("db: shmctl: %s",mstrerror(errno));
// log it
log("db: allocated %"INT32" bytes shmid=%"INT32"",alloc,(int32_t)shmid);
// add it to our list
m_shmids [ m_numShmids ] = shmid;
m_shmidSize [ m_numShmids ] = alloc;
m_numShmids++;
// count it
g_mem.m_sharedUsed += alloc;
// log it for now
//logf(LOG_DEBUG,"db: new shmid id is %"INT32", size=%"INT32"",
// (int32_t)shmid,(int32_t)alloc);
// subtract it
need -= alloc;
// get more
if ( need > 0 ) goto shmloop;
}
#endif
*/
// a malloc tag, must be LESS THAN 16 bytes including the NULL
char *p = m_memTag;
gbmemcpy ( p , "pgcache-" , 8 ); p += 8;
if ( dbname ) strncpy ( p , dbname , 8 );
// so we know what db we are caching for
m_dbname = p;
p += 8;
*p++ = '\0';
// sanity check, we store bytes used as a int16_t at top of page
//if ( m_diskPageSize > 0x7fff ) { char *xx = NULL; *xx = 0; }
// . do not use more than this much memory for caching
// . it may go over by like 2% for header information
m_maxMem = maxMem ;
// set m_pageSetSize. use this now instead of m_maxPageSetSize #define
int32_t phsize = pageSize + HEADERSIZE;
m_maxPageSetSize = (((128*1024*1024)/phsize)*phsize);
m_diskPageSize = pageSize;
m_minimizeDiskSeeks = minimizeDiskSeeks;
// we need to keep a count memory of files being cached
if ( m_minimizeDiskSeeks )
m_memFree = m_maxMem;
// check for overriding functions
//if ( getPages2 && addPages2 && getVfd2 && rmVfd2 ) {
// // set override flag
// m_isOverriden = true;
// // set override functions
// m_getPages2 = getPages2;
// m_addPages2 = addPages2;
// m_getVfd2 = getVfd2;
// m_rmVfd2 = rmVfd2;
// // return here
// return true;
//}
/*
// for now only indexdb will use the ramdisk
if ( strcmp ( dbname, "indexdb" ) == 0 && useRAMDisk ){
if ( !initRAMDisk( dbname, maxMem ) )
return log ( "db: failed to init RAM disk" );
}
*/
// . use up to 800k for starters
// . it will grow more as needed
if ( ! growCache ( maxMem ) )
return log("db: pagecache init failed: %s.",
mstrerror(g_errno));
// success
return true;
}
// use Linux's ram disk for caching disk pages, in addition to the ram it
// already uses. I would like to be able to pass in a "maxMemForRamDisk" parm
// to its init() function and have it open a single, ram-disk file descriptor
// for writing up to that many bytes.
// then i would like only Indexdb (and later on Datedb) to pass in an 800MB
// "maxMemForRamDisk" value, and, furthermore, i do not want to cache disk
// pages from the indexdb root file, nor, any indexdb file that is larger than
// twice the "maxMemForRamDisk" value (in this case 1.6GB). this will be used
// exclusively for smaller indexdb files to eliminate excessive disk seeks and
// utilize ALL the 4GB of ram in each machine.
// lastly, we need some way to "force" a merge at around midnight when traffic
// is minimal, or when there are 3 or more indexdb files that are less than
// 80% in the indexdb disk page cache. because that means we are starting to
// do a lot of disk seeks.
/*
bool DiskPageCache::initRAMDisk( const char *dbname, int32_t maxMem ){
m_useRAMDisk = true;
if ( !dbname ) {char *xx=NULL; *xx=0;}
// open a file descriptor
char ff [1024];
sprintf ( ff, "/mnt/RAMDisk/%sPageCache", dbname );
// unlink it first
unlink (ff);
m_ramfd = open ( ff, O_RDWR | O_CREAT );
if ( m_ramfd < 0 )
return log ( LOG_WARN,"db: could not open fd in RAMdisk" );
return true;
}
*/
// . this returns true iff the entire read was copied into
// "buf" from the page cache
// . it will move the used pages to the head of the linked list
// . if *buf is NULL we allocate here
void DiskPageCache::getPages ( int32_t vfd ,
char **buf ,
int32_t numBytes ,
int64_t diskOffset ,
int32_t *newNumBytes ,
int64_t *newOffset ,
char **allocBuf ,
int32_t *allocSize ,
int32_t allocOff ) {
// check for override function
//if ( m_isOverriden ) {
// //log ( LOG_INFO, "cache: Get Pages [%"INT32"] [%"INT32"][%"INT64"]",
// // vfd, numBytes, offset );
// m_getPages2 ( this,
// vfd,
// buf,
// numBytes,
// offset,
// newNumBytes,
// newOffset );
// return;
//}
// return new disk offset, assume unchanged
*newOffset = diskOffset;
*newNumBytes = numBytes;
// return if no pages allowed in page cache
if ( m_maxMem == 0 ) return;
// or disabled
if ( ! m_enabled ) return;
// disabled at the master controls?
if ( m_switch && ! *m_switch ) return;
// or if minimizeDiskSeeks did not accept the vfd
if ( m_minimizeDiskSeeks && vfd < 0 )
return;
// or if no pages in this vfd
if ( ! m_memOffFromDiskPage[vfd] )
return;
// debug point
//if ( offset == 16386 && numBytes == 16386 )
// log("hey");
// what is the page range of in-memory pages?
int32_t sp = diskOffset / m_diskPageSize ;
int32_t ep = (diskOffset + (numBytes-1)) / m_diskPageSize ;
// . sanity check
// . we establish the maxPagesInFile when BigFile::open is called
// by RdbDump. Rdb.cpp calls m_dump.set with a maxFileSize based on
// the mem occupied by the RdbTree. BUT,recs can be added to the tree
// WHILE we are dumping, so we end up with a bigger file, and this
// disk page cache is not prepared for it!
if ( ep >= m_maxPagesInFile[vfd] ) {
// happens because rdbdump did not get a high enough
// maxfilesize so we did not make enough pages! we endedup
// dumping more than what was end the tree because stuff was
// added to the tree while dumping!
log("db: pagecache: Caught get breach. "
"ep=%"INT32" max=%"INT32" vfd=%"INT32""
, ep,m_maxPagesInFile[vfd] ,vfd);
return;
//char *xx = NULL; *xx = 0;
}
char *bufPtr = *buf;
char *bufEnd = *buf + numBytes;
// our offset into first page on disk ( as well as memory page)
int32_t start1 = diskOffset - sp * m_diskPageSize;
// this is for second while loop
int32_t start2 = 0;
if ( ep == sp ) start2 = start1;
// store start pages
while ( sp <= ep ) {
// map disk page # sp into memory offset, "poff"
int32_t poff = m_memOffFromDiskPage[vfd][sp];
// get a ptr to it
//char *s = getMemPtrFromMemOff ( poff );
//if ( ! s ) break;
// break if we do not have page in memory
if ( poff < 0 ) break;
// first 4 bytes of page is how many bytes are used in page
int32_t size = 0;
readFromCache( &size, poff, OFF_SIZE, sizeof(int32_t));
//int32_t size = *(int32_t *)(s+OFF_SIZE);
// second set of 4 bytes is offset of data from page boundary
int32_t skip = 0;
readFromCache( &skip, poff, OFF_SKIP, sizeof(int32_t));
//int32_t skip = *(int32_t *)(s+OFF_SKIP);
// debug msg
// log("getPage: pageNum=%"INT32" poff=%"INT32" size=%"INT32" "
// "skip=%"INT32"",
// sp,poff,(int32_t)size,(int32_t)skip);
// if this mem page data starts AFTER our offset, it is no good
if ( skip > start1 ) break;
// adjust size by our page offset, we won't necessarily be
// starting our read at "skip"
size -= (start1 - skip);
// if size is 0 or less all cached data was
// below our disk offset and is useless
if ( size <= 0 ) break;
// . promote this memory page in the linked list
// . 16 byte header of each memory page houses the
// linked lists' next and prev ptrs to pages in memory
// just for putting the most frequently used pages on top
promotePage ( poff , false );
// allocate the read buffer if we need to
if ( ! *buf ) {
// allocate enough room for allocOff, too
int32_t need = numBytes + allocOff;
char *p = (char *) mmalloc ( need,"PageCacheReadBuf" );
// let FileState know what needs to be freed
*allocBuf = p;
*allocSize = need;
// if couldn't allocate, return now, what's the point
if ( ! p ) return;
// let caller know his new read buffer
*buf = p + allocOff;
// assign the ptrs now
bufPtr = *buf ;
bufEnd = *buf + numBytes;
}
// don't store more than asked for
if ( bufPtr + size > bufEnd ) size = bufEnd - bufPtr;
// . read in "size" bytes from memory into "bufPtr"
// . start reading at an offset of "HEADERSIZE+start1" into
// the memory page
readFromCache(bufPtr, poff, HEADERSIZE + start1 , size);
//gbmemcpy ( bufPtr , s + HEADERSIZE + start1 , size );
bufPtr += size;
*newOffset += size;
*newNumBytes -= size;
// return if we got it all
if ( bufPtr >= bufEnd ) { m_hits += 1; return; }
// otherwise, advance to next page
sp++;
// and our page relative offset is zero now, iff ep > sp
if ( sp <= ep ) start1 = 0;
// if the memory page ended before the disk page, break out
// because we don't want any holes
readFromCache( &size, poff, OFF_SIZE, sizeof(int32_t));
if ( skip + size < m_diskPageSize ) break;
//if ( skip + *(int32_t *)(s+OFF_SIZE) < m_diskPageSize )break;
}
// now store from tail down
/*
while ( ep > sp ) {
// the page offset in memory
int32_t poff = m_memOffFromDiskPage[vfd][ep];
// get a ptr to it
char *s = getMemPtrFromMemOff ( poff );
// break if we do not have page in memory
if ( ! s ) break;
// first 2 bytes of page is how many bytes are used
int32_t size = *(int32_t *)s;
// second set of 2 bytes is offset from boundary
int32_t skip = *(int32_t *)(s+OFF_SKIP);
// adjust size by our page offset, if not zero
if ( start2 > skip ) size -= (start2 - skip);
// his skip point could be beyond us, too
if ( skip >
// . promote this page in the linked list
// . bytes 8-16 of each page in memory houses the
// next and prev ptrs to pages in memory
promotePage ( s , poff , false );
// don't store more than asked for
if ( bufEnd - size < bufPtr ) size = bufEnd - bufPtr;
gbmemcpy ( bufEnd - size , s + HEADERSIZE + start2 , size );
bufEnd -= size;
*newNumBytes -= size;
// return if we got it all
if ( bufEnd <= bufPtr ) { m_hits += 1; return; }
// if this page had a skip, break out, we don't wany any holes
if ( skip > 0 ) break;
// otherwise, advance to next page
ep--;
}
*/
m_misses += 1;
}
// after you read/write from/to disk, copy into the page cache
void DiskPageCache::addPages ( int32_t vfd,
char *buf,
int32_t numBytes,
int64_t diskOffset ,
int32_t niceness ){
// check for override function
//if ( m_isOverriden ) {
// m_addPages2 ( this,
// vfd,
// buf,
// numBytes,
// offset );
// return;
//}
// if vfd is -1, then we were not able to add a map for this file
if ( vfd < 0 ) return;
// no NULL ptrs
if ( ! buf ) return;
// return if no pages allowed in page cache
if ( m_maxMem == 0 ) return;
// or disabled
if ( ! m_enabled ) return;
// disabled at the master controls?
if ( m_switch && ! *m_switch ) return;
// sometimes the file got unlinked on us
if ( ! m_memOffFromDiskPage[vfd] ) return;
// for some reason profiler cores all the time in here
//if ( g_profiler.m_realTimeProfilerRunning ) return;
// . "diskPageNum" is the first DISK page #
// . "offset" is the offset on disk the data was read from
// . "m_diskPageSize" is the size of the disk pages
int64_t diskPageNum = diskOffset / m_diskPageSize ;
// point to the data that was read from disk
char *bufPtr = buf;
char *bufEnd = buf + numBytes;
// . how much did we exceed the mem page boundary by?
// . "skip" is offset into the memory page where we store the disk data
int32_t skip = diskOffset - diskPageNum * m_diskPageSize ;
// how many bytes of disk data should we store into the memory page?
int32_t size = m_diskPageSize - skip;
// now add the remaining data into memory pages
while ( bufPtr < bufEnd ) {
// breathe
QUICKPOLL(niceness);
// ensure "size" is not too big.
// adjust "size" if so,so we won't exceed the mem page boundary
if ( bufPtr + size > bufEnd ) size = bufEnd - bufPtr;
// add the page to memory.
// "bufPtr" is the data we read from disk.
// "size" is where to start writing relative to this memory
// page's start.
// "skip" is how many bytes to write into this "page".
addPage ( vfd , diskPageNum , bufPtr , size , skip );
// advance disk data buf over what we stored into the mem page
bufPtr += size;
// advance DISK page #
diskPageNum++;
// assume we will be filling up the next mem page fully
size = m_diskPageSize;
// skip is offset from beginning of the memory page
skip = 0;
}
}
// . convert our MEMORY offset into an actual ptr to a chunk of memory
// . this makes our memory pooling approach transparent
// . "off" is offset into the memory
// . "off" includes HEADERSIZE headers in it
char *DiskPageCache::getMemPtrFromMemOff ( int32_t off ) {
if ( off < 0 ) return NULL; // NULL means not in DiskPageCache
// for some reason profiler cores all the time in here
// and m_numPageSets is 0 like we got reset
//if ( g_profiler.m_realTimeProfilerRunning ) return NULL;
// get set number
int32_t sn = off / m_maxPageSetSize ;
// get offset from within the chunk of memory (within the set)
//int32_t poff = off & (m_maxPageSetSize-1);
int32_t poff = off % (m_maxPageSetSize);
// . sanity check
// . offset must be multiple of m_diskPageSize+HEADERSIZE, no cuz we skip
// ahead X bytes of a page set boundary...
//int32_t off2 = off - sn * m_maxPageSetSize;
//if ( off2 != 0 && (off2% (m_diskPageSize+HEADERSIZE)) != 0) {
// char *xx = NULL; *xx = 0; }
// if we are not in the first page set, advance by one chunk
// because the first page is often mapped to by a truncated poff from
// the previous page set
//if ( sn > 0 && poff == 0 ) poff += m_diskPageSize + HEADER_SIZE;
// if it would breech our PAGE_SET, up it
if ( poff + m_diskPageSize + HEADERSIZE > m_maxPageSetSize) {poff=0; sn++;}
// sanity check
if ( sn >= m_numPageSets ) { char *xx = NULL; *xx = 0; }
// return the proper ptr
return (m_pageSet[sn]) + poff;
}
// . "diskPageNum" is the disk page # of the file with "vfd"
// . "page" points to the disk data we read from disk
// . "size" is how many bytes to write into the memory page, #pageNum
// . "skip" is the offset into the memory page we will write the disk data into
void DiskPageCache::addPage(int32_t vfd,
int32_t diskPageNum,
char *pageData,
int32_t size,
int32_t skip){
// . if pageNum is beyond the file size
// . see the explanation for this same error msg above
if ( diskPageNum >= m_maxPagesInFile[vfd] ) {
// this has happened during a merge before!! (at startup)
//log(LOG_LOGIC,"db: pagecache: addPage: Bad engineer. "
// happens because rdbdump did not get a high enough
// maxfilesize so we did not make enough pages! we endedup
// dumping more than what was end the tree because stuff was
// added to the tree while dumping!
log("db: pagecache: Caught add breach. "
"pageNum=%"INT32" max=%"INT32" db=%s",
diskPageNum,m_maxPagesInFile[vfd],m_dbname);
return;
}
// debug msg
// log("addPage: vfd=%"INT32" diskPageNum=%"INT32" pageData[0]=%hhx "
// "size=%"INT32" skip=%"INT32"",
// vfd,diskPageNum,pageData[0],size,(int32_t)skip);
// "poff" is the DISK page # for "vfd" (virtual file descriptor) and
// it returns an offset to the page in memory.
int32_t poff = m_memOffFromDiskPage [ vfd ] [ diskPageNum ] ;
int32_t oldDiskPage;
// p will be NULL if page does not have any data in memory yet
//char *p = getMemPtrFromMemOff ( poff );
// if page already exists in cache and needs data on the boundaries
// we may be able to supply it
if ( poff >= 0 ) {
// debug msg
//log("ENHANCING off=%"INT32"",poff);
enhancePage ( poff , pageData , size , skip );
return;
}
// don't add any more if we're minimizing disk seeks and are full
if ( m_minimizeDiskSeeks &&
m_numPagesPresentOfFile[vfd] >= m_maxPagesPerFile[vfd] )
return;
// top:
// try to get an available memory spot from list
if ( m_numAvailMemOffs > 0 ) {
poff = m_availMemOff [ --m_numAvailMemOffs ] ;
// debug msg
//log("RECYCLING off=%"INT32" numAvailMemOffs-1=%"INT32""
// ,poff,m_numAvailMemOffs);
}
// can we grab a page from memory without having to grow?
else if ( m_nextMemOff + m_diskPageSize + HEADERSIZE < m_upperMemOff) {
poff = m_nextMemOff;
m_nextMemOff += m_diskPageSize + HEADERSIZE;
// debug msg
// log("CLAIMING off=%"INT32" (nextmemoff=%"INT32"",poff,
// m_nextMemOff);
}
// . we now grow everything at start
// . otherwise, try to grow the page cache by 200k
//else if ( m_nextMemOff + m_diskPageSize + HEADERSIZE < m_maxMem ) {
// // grow by 100k worth of pages each time
// if ( ! growCache ( m_upperMemOff + 200*1024 ) ) return;
// goto top;
//}
// this should never happen. Since in minimizeDiskSeek we have
// an exact number of pages per file
else if ( m_minimizeDiskSeeks ) {
char *xx = NULL; *xx = 0;
}
// if no freebies left, take over the tail page in memory
else {
// STEAL IT!!
poff = m_tailOff;
// remove it from linked list. it will be re-added below @ head
////
// CAUTION: THIS CHANGES m_tailOff!!!!!!
///
excisePage ( m_tailOff );
// . the file no longer owns him
// . this is a int32_t ptr to &m_bufOffs[vfd][pageNum]
// . if that vfd no longer exists it should have added all its
// pages to m_avail list
//int32_t tmp = -1;
// WHY DOING THIS?
//int32_t memOff = -1;//NULL;
//readFromCache(&memOff, poff, OFF_PTR, sizeof(int32_t));
// the tail may actualy belong to a separated file with
// a different vfd
int oldVfd;
readFromCache (&oldVfd,poff,OFF_VFD,sizeof(int32_t));
readFromCache (&oldDiskPage,poff,OFF_DISKPAGENUM,
sizeof(int32_t));
// did excise work?
// this cored here from m_memOffFroMDiskPage[oldVfd] being
// NULL, so how could that happen?
if ( m_memOffFromDiskPage[oldVfd] &&
m_memOffFromDiskPage[oldVfd][oldDiskPage] != -1 ) {
char *xx=NULL;*xx=0; }
// did ex
// seg faultint here: mdw:
//*memOffPtr = -1;
// how can this be, we subverted a valid buffer
//if ( memOff == -1 ) { char *xx=NULL;*xx=0; }
//poff = memOff;
//m_cacheBuf.writeToCache(poff, OFF_PTR, &tmp, sizeof(int32_t));
// testing
//m_cacheBuf.readFromCache ( &tmp, poff+OFF_PTR, sizeof(int32_t) );
//if ( tmp != -1 ){
//char *xx=NULL; *xx=0;}
//**(int32_t **)(p+OFF_PTR) = -1;
// debug msg
//log("KICKINGTAIL off=%"INT32"",poff);
}
// sanity check
if ( poff < 0 ) { char *xx = NULL; *xx = 0; }
// get ptr to the page in memory from the memory offset
//p = getMemPtrFromMemOff ( poff );
// store how many bytes we wrote into the memory page residing @ poff
writeToCache(poff, OFF_SIZE, &size, sizeof(int32_t));
// int32_t tmp = 0;
// m_cacheBuf.readFromCache ( &tmp, poff, OFF_SIZE, sizeof(int32_t) );
// if ( tmp != size ){
// char *xx=NULL; *xx=0;}
//*(int32_t *)(p+OFF_SIZE) = size;
// store "skip" which is the offset into the memory page we start
// storing the disk data into
writeToCache( poff, OFF_SKIP, &skip, sizeof(int32_t) );
//*(int32_t *)(p+OFF_SKIP) = skip;
// sanity check
if ( size + skip > m_diskPageSize ) { char *xx = NULL; *xx = 0; }
// then store a ptr to m_memOffFromDiskPage[vfd][pageNum] so we can set
// *ptr to -1 if they page gets replaced by another
// store the offset of this memory page
//int32_t *memOffPtr = &m_memOffFromDiskPage[ vfd ][ pageNum ];
// m_memOffFromDiskPage maps a vfd/pagenum to a memory page offset.
// -1 means none.
// why do we need to store the memory offset in the memory page???
//int32_t memOff = m_memOffFromDiskPage[ vfd ][ pageNum ];
//writeToCache( poff, OFF_PTR, &memOff, sizeof(int32_t));
//*(int32_t **)(p+OFF_PTR) = &m_memOffFromDiskPage [ vfd ] [ pageNum ];
// then the data from disk (skip over linked list info)
// "skip" is how far into the memory page we should write the
// disk data because it is not aligned perfectly with the mem page.
writeToCache( poff, HEADERSIZE + skip, pageData, size);
//gbmemcpy ( p + HEADERSIZE + skip , page , size );
// transform mem ptr to memory offset
//if ( !m_useRAMDisk && ! m_useSHM ) {
/*
int32_t off = -1;
char *p = getMemPtrFromMemOff ( poff );
for ( int32_t i = 0 ; i < m_numPageSets ; i++ ) {
if ( p < m_pageSet[i] ) continue;
if ( p > m_pageSet[i] + m_pageSetSize[i] )
continue;
off = p - m_pageSet[i] + i * m_maxPageSetSize ;
break;
}
*/
// gotta record this now too!
writeToCache( poff, OFF_DISKPAGENUM, &diskPageNum, sizeof(int32_t) );
writeToCache( poff, OFF_VFD, &vfd, sizeof(int32_t) );
// store the linked list information in the remaining header bytes
// that we use for promoting heaviliy hit pages to the top of
// thereby replacing the tail when adding new pages. this will
// insert our page into the linked list. it will set the prev/next
// mem page offsets in the header of this memory page.
promotePage ( poff , true/*isNew?*/ );
// update map. map disk page # to mem offset.
m_memOffFromDiskPage [ vfd ] [ diskPageNum ] = poff;
// sanity check
//if ( off != poff ) { char *xx=NULL; *xx=0; }
//}
//else
// m_memOffFromDiskPage [ vfd ] [ pageNum ] = poff;
// update the header of that page
// we have added the page!
if ( m_minimizeDiskSeeks )
m_numPagesPresentOfFile[vfd]++;
}
// . add data from "page" (we just read it from disk or wrote to disk)
// . "poff" is the memory page # that will receive the disk data
// . "page" points to the disk data we read from disk to be stored into mem pg
// . "size" is how many bytes to write into the memory page, #pageNum
// . "skip" is the offset into the memory page we will write the disk data into
void DiskPageCache::enhancePage (int32_t poff, char *page, int32_t size,
int32_t skip) {
int32_t psize = 0;
readFromCache( &psize, poff, OFF_SIZE, sizeof(int32_t));
//int32_t psize = *(int32_t *)(p+OFF_SIZE);
int32_t pskip = 0;
readFromCache( &pskip, poff, OFF_SKIP, sizeof(int32_t));
//int32_t pskip = *(int32_t *)(p+OFF_SKIP);
// can we add to front of page?
if ( skip < pskip ) {
int32_t diff = pskip - skip;
// . we cored here because page[diff-1] was out of bounds. why?
// . do not allow gap in between cached data, that is, we have
// cached bytes at the end of the page, then we try to cache
// some at the beginning, and it's not contiguous... we are
// not built for that... this can happen when dumping a file,
// if your first reads up to the file end (somewhere in the
// middle of the page) and your second read starts somewhere
// else.... mmmm... i dunno....
if ( skip + size < pskip || diff > size ) {
log("db: Avoided cache gap in %s. diff=%"INT32" "
"size=%"INT32" pskip=%"INT32" skip=%"INT32".",
m_dbname,diff,size,(int32_t)pskip,(int32_t)skip);
return;
}
writeToCache(poff, HEADERSIZE + skip , page , diff);
//gbmemcpy ( p + HEADERSIZE + skip , page , diff );
psize += diff;
pskip -= diff;
writeToCache(poff, OFF_SIZE, &psize, sizeof(int32_t));
//*(int32_t *)(p+OFF_SIZE) = psize ;
writeToCache(poff, OFF_SKIP, &pskip, sizeof(int32_t));
//*(int32_t *)(p+OFF_SKIP) = pskip ;
}
// can we add to end of page?
int32_t pend = pskip + psize;
int32_t end = skip + size;
if ( end <= pend ) return;
int32_t diff = end - pend ;
// if the read's starting point is beyond our ending point, bail,
// we don't want any holes...
if ( diff > size ) return;
writeToCache(poff, HEADERSIZE + pend, page + size - diff, diff);
//gbmemcpy ( p + HEADERSIZE + pend , page + size - diff , diff );
int32_t tmp = psize+diff;
writeToCache(poff, OFF_SIZE, &tmp, sizeof(int32_t));
//*(int32_t *)(p+OFF_SIZE) = (int32_t)psize + diff;
}
// the link information is bytes 8-16 of each page in mem (next/prev mem ptrs)
void DiskPageCache::promotePage ( int32_t poff , bool isNew ) {
if ( isNew ) {
here:
// store a -1 to indicate previous page offset.
// we are the head of the linked list now, so -1 means none.
int32_t tmp = -1;
writeToCache(poff, OFF_PREV, &tmp, sizeof(int32_t));
// testing
readFromCache ( &tmp, poff, OFF_PREV, sizeof(int32_t) );
if ( tmp != -1 ){
char *xx=NULL; *xx=0;}
//*(int32_t *)(p + OFF_PREV) = -1 ;// our prev is -1 (none)
// store the next page in the linked list who WAS the head
// it could be -1 if we are the first entry intothe linked list
writeToCache(poff, OFF_NEXT, &m_headOff, sizeof(int32_t));
//*(int32_t *)(p+OFF_NEXT)=m_headOff;//our next is the old head
// the old head's prev is us
if ( m_headOff >= 0 ) {
writeToCache(m_headOff,OFF_PREV,&poff,sizeof(int32_t));
//char *headPtr = getMemPtrFromMemOff ( m_headOff ) ;
//*(int32_t *)(headPtr + OFF_PREV) = poff;
}
// and we're the new head
m_headOff = poff;
// if no tail, we become that, too, we must be the first
if ( m_tailOff < 0 ) m_tailOff = poff;
return;
}
// otherwise, we have to excise
excisePage ( poff );
// and add as new
goto here;
}
// remove a page from the linked list
void DiskPageCache::excisePage ( int32_t poff ) {
// get our neighbors, NULL if none
int32_t prev = 0;
readFromCache(&prev, poff, OFF_PREV, sizeof(int32_t));
//int32_t prev = *(int32_t *)(p + OFF_PREV);
int32_t next = 0;
readFromCache(&next, poff, OFF_NEXT, sizeof(int32_t));
//int32_t next = *(int32_t *)(p + OFF_NEXT);
// if we were the head or tail, then pass it off to our neighbor
if ( poff == m_headOff ) m_headOff = next;
if ( poff == m_tailOff ) m_tailOff = prev;
// our prev's next becomes our old next
if ( prev >= 0 ) {
//char *prevPtr = getMemPtrFromMemOff ( prev );
writeToCache(prev, OFF_NEXT, &next, sizeof(int32_t));
//*(int32_t *)(prevPtr + OFF_NEXT ) = next;
}
// our next's prev becomes our old prev
if ( next >= 0 ) {
//char *nextPtr = getMemPtrFromMemOff ( next );
writeToCache(next, OFF_PREV, &prev, sizeof(int32_t));
//int32_t *)(nextPtr + OFF_PREV ) = prev;
}
// what is the tail's disk page # so we can update
// m_memOffFromDiskPage[vfd][tailDiskPageNum] ?
int32_t diskPageNum;
readFromCache ( &diskPageNum,poff,OFF_DISKPAGENUM,sizeof(int32_t) );
int vfd;
readFromCache ( &vfd,poff,OFF_VFD,sizeof(int32_t) );
// the memory page we are commandeering should no longer be
// mapped to from its disk page
if ( m_memOffFromDiskPage [ vfd ] )
m_memOffFromDiskPage [ vfd ] [ diskPageNum ] = -1;
}
// . grow/shrink m_memOffFromDiskPage[] which maps vfd/page to a mem offset
// . returns false and sets g_errno on error
// . called by DiskPageCache::open()/close() respectively
// . fileSize is so we can alloc m_memOffFromDiskPage[vfd] big enough
// for all pgs
int32_t DiskPageCache::getVfd ( int64_t maxFileSize, bool vfdAllowed ) {
// check for override function
//if ( m_isOverriden ) {
// return m_getVfd2 ( this, maxFileSize );
//}
// for RAMDisks, do not cache disk
// pages from the indexdb root file, nor, any indexdb file that is
// larger than twice the "maxMemForRamDisk" value
/*
if ( m_useRAMDisk && maxFileSize > (m_maxMem * 2) ){
log (LOG_INFO,"db: getvfd: cannot cache on RAMDisk files that "
"larger than twice the max mem value. fileSize=%"INT32"",
m_maxMem);
return -1;
}
*/
int32_t numPages = (maxFileSize / m_diskPageSize) + 1;
// RESTRICT to only the first m_maxMemOff worth of files,
// starting with the SMALLEST file first. so if maxMemoff is 50MB, and
// we have 5 files that are 10,20,30 & 40MB,
// then we use 10MB for the first file, 20MB of the 2nd BUT only
// 20MB for the 3rd file, and the 4th file does not get any page cache.
// if doing "biased lookups" each file is virtually half the actual
// size, and this allocates page cache appropriately.
// don't to do a page cache for an indexdb0001.dat that is 100GB
// because we'd have to allocate too much mem for the
// m_memOffFromDiskPage[] array
// so for the parital file make sure its less than 1 GB
if ( m_minimizeDiskSeeks && !vfdAllowed ){
log (LOG_INFO,"db: getVfd: cannot cache because minimizing "
"disk seeks. numPages=%"INT32"", numPages);
return -1;
}
// . pick a vfd for this BigFile to use
// . start AFTER last pick in case BigFile closed, released its
// m_vfd, a read thread returned and called addPages() using that
// old m_vfd!!!!!!! TODO: can we fix this better?
int32_t i ;
int32_t count = MAX_NUM_VFDS2;
for ( i = m_nexti ; count-- > 0 ; i++ ) {
if ( i >= MAX_NUM_VFDS2 ) i = 0; // wrap
if ( ! m_memOffFromDiskPage [ i ] ) break;
}
// bail if none left
if ( count == 0 ) {
g_errno = EBADENGINEER;
log(LOG_LOGIC,"db: pagecache: getvfd: no vfds remaining.");
//char *xx = NULL; *xx = 0;
return -1;
}
// . file size has to be below 2 gigs because m_memOffFromDiskPage is
// only a int32_t
// . if we need to we could transform m_memOffFromDiskPage into
// m_memPageNum
//if ( maxFileSize > 0x7fffffffLL ) {
// g_errno = EBADENGINEER;
// log("DiskPageCache::getVfd: maxFileSize too big");
// return -1;
//}
// assign it
int32_t vfd = i;
// start here next time
m_nexti = i + 1;
// say which cache it is
// alloc the map space for this file
int32_t need = numPages * sizeof(int32_t) ;
int32_t *buf = (int32_t *)mmalloc ( need , m_memTag );
if ( ! buf ) {
log("db: Failed to allocate %"INT32" bytes for page cache "
"structures for caching pages for vfd %"INT32". "
"MaxfileSize=%"INT64". Not enough memory.",
need,i,maxFileSize);
return -1;
}
m_memOffFromDiskPage [ vfd ] = buf;
m_maxPagesInFile [ vfd ] = numPages;
// keep a tab on the number of pages we can store of the file
if ( m_minimizeDiskSeeks ){
m_numPagesPresentOfFile[vfd] = 0;
if ( m_memFree > numPages * ( HEADERSIZE + m_diskPageSize ) )
m_maxPagesPerFile[vfd] = numPages;
else
m_maxPagesPerFile[vfd] = m_memFree / ( m_diskPageSize +
HEADERSIZE );
}
// add it in
m_memAlloced += need;
// debug msg
//log("%s adding %"INT32"",m_dbname,need);
// no pages are in memory yet, so set offsets to -1
for ( i = 0 ; i < numPages ; i++ )
m_memOffFromDiskPage [ vfd ] [ i ] = -1;
// if minimizing disk seeks then calculate the memory used
if ( m_minimizeDiskSeeks ){
m_memFree -= maxFileSize;
// if the file is bigger than the mem only partially store it
if ( m_memFree < 0 )
m_memFree = 0;
}
// debug msg
//log("ALLOCINGFILE pages=%"INT32"",numPages);
return vfd;
}
// when a file loses its vfd this is called
void DiskPageCache::rmVfd ( int32_t vfd ) {
// check for override function
//if ( m_isOverriden ) {
// m_rmVfd2 ( this, vfd );
// return;
//}
// ensure validity
if ( vfd < 0 ) return;
// if 0 bytes are allocated for disk cache, just skip this junk
if ( m_maxMem <= 0 ) return;
// this vfd may have already been nuked by call to unlink!
if ( ! m_memOffFromDiskPage [ vfd ] ) return;
// add valid offsets used by vfd into m_availMemOff
for ( int32_t i = 0 ; i < m_maxPagesInFile [ vfd ] ; i++ ) {
int32_t off = m_memOffFromDiskPage [ vfd ] [ i ];
// a -1 offset means empty
if ( off < 0 ) continue;
// sanity check
if ( m_numAvailMemOffs >= m_maxAvailMemOffs ) {
char *xx = NULL; *xx = 0; }
// debug msg
//log("MAKING off=%"INT32" available. na=%"INT32"",
// off,m_numAvailMemOffs+1);
// store it in list of available memory offsets so some other
// file can use it
m_availMemOff [ m_numAvailMemOffs++ ] = off;
//log("disk: m_numAvailMemOffs+1 -> %"INT32,m_numAvailMemOffs);
// set this to -1 i guess. it'll be freed below anyway.
m_memOffFromDiskPage [ vfd ] [i] = -1;
// remove that page from linked list, too
//char *p = getMemPtrFromMemOff ( off );
excisePage ( off );
}
// free the map that maps this files pages on disk to pages/offs in mem
int32_t size = m_maxPagesInFile[vfd] * sizeof(int32_t);
mfree ( m_memOffFromDiskPage [ vfd ] , size , "DiskPageCache" );
m_memOffFromDiskPage [ vfd ] = NULL;
// debug msg
//log("%s rmVfd: vfd=%"INT32" down %"INT32"",m_dbname,vfd,size);
m_memAlloced -= size;
if ( m_minimizeDiskSeeks ){
m_memFree += m_maxPagesPerFile[vfd] * m_diskPageSize;
m_maxPagesPerFile[vfd] = 0;
m_numPagesPresentOfFile[vfd] = 0;
}
}
// use "mem" bytes of memory for the cache
bool DiskPageCache::growCache ( int32_t mem ) {
// debug msg
//log("GROWING PAGE CACHE from %"INT32" to %"INT32" bytes (%"XINT64")"
// ,m_upperMemOff, mem ,(uint64_t)this);
// don't exceed the max
if ( mem > m_maxMem ) mem = m_maxMem;
// bail if we wouldn't be growing
if ( mem <= m_upperMemOff ) return true;
// how many pages? round up.
int32_t npages = mem/(m_diskPageSize+HEADERSIZE) + 1;
// . we need one "available" slot for each page in the cache
// . this is a list of memory offsets that are available
int32_t oldSize = m_maxAvailMemOffs * sizeof(int32_t) ;
int32_t newSize = npages * sizeof(int32_t) ;
int32_t *a=(int32_t *)mrealloc(m_availMemOff,oldSize,newSize,m_memTag);
if ( ! a ) return log("db: Failed to regrow page cache from %"INT32" to "
"%"INT32" bytes. Not enough memory.",oldSize,newSize);
m_availMemOff = a;
m_maxAvailMemOffs = npages;
m_memAlloced += (newSize - oldSize);
// debug msg
//log("%s growCache: up %"INT32"",m_dbname,(newSize - oldSize));
// how much more mem do we need to alloc?
int32_t need = mem - m_upperMemOff ;
// how big is our last page set?
int32_t size = 0;
char *ptr = NULL;
int32_t i = 0;
if ( m_numPageSets > 0 ) {
// since we allocate everything at init this shouldn't happen
char *xx=NULL; *xx=0;
i = m_numPageSets - 1;
ptr = m_pageSet [ i ];
size = m_pageSetSize [ i ];
}
// realloc him
int32_t extra = m_maxPageSetSize - size ;
if ( extra > need ) extra = need;
/*
if ( m_useRAMDisk ){
// since RAMdisk it creates a file, no reason to alloc
m_memAlloced = need;
m_upperMemOff = need;
return true;
}
// and shared mem already has the mem at this point
if ( m_useSHM ) {
m_memAlloced = need;
m_upperMemOff = need;
return true;
}
*/
char *s = (char *)mrealloc ( ptr , size , size + extra,
m_memTag);
if ( ! s ) return log("db: Failed to allocate %"INT32" bytes more "
"for pagecache.",extra);
m_pageSet [ i ] = s;
m_pageSetSize [ i ] = size + extra;
// if we are not adding to an existing, we are a new page set
if ( ! ptr ) m_numPageSets++;
// discount it
need -= extra;
// add to alloc count
m_memAlloced += extra;
m_upperMemOff += extra;
// debug msg
//log("%s growCache2: up %"INT32"",m_dbname,extra);
// if we do not need more, we are done
if ( need == 0 ) return true;
// otherwise, alloc new page sets until we hit it
for ( i++ ; i < MAX_PAGE_SETS && need > 0 ; i++ ) {
int32_t size = need;
if ( size > m_maxPageSetSize ) size = m_maxPageSetSize;
need -= size;
m_pageSet[i] = (char *) mmalloc ( size , m_memTag );
if ( ! m_pageSet[i] ) break;
m_pageSetSize[i] = size;
m_memAlloced += size;
m_upperMemOff += size;
m_numPageSets++;
// debug msg
//log("%s growCache3: up %"INT32"",m_dbname,size);
}
// update upper bound
if ( need == 0 ) return true;
return log(LOG_LOGIC,"db: pagecache: Bad engineer. Weird problem.");
}
int32_t DiskPageCache::getMemUsed ( ) {
return m_nextMemOff - m_numAvailMemOffs * (m_diskPageSize+HEADERSIZE);
}
bool DiskPageCache::verifyData2 ( int32_t vfd ) {
// ensure validity
//if ( vfd < 0 ) return true;
for ( int vfd = 0 ; vfd < 10 ; vfd++ ) {
// this vfd may have already been nuked by call to unlink!
if ( ! m_memOffFromDiskPage [ vfd ] ) continue;//return true;
// debug msg
//log("VERIFYING PAGECACHE vfd=%"INT32" fn=%s",vfd,f->getFilename());
// read into here
// add valid offsets used by vfd into m_availMemOff
for ( int32_t i = 0 ; i < m_maxPagesInFile [ vfd ] ; i++ ) {
int32_t off = m_memOffFromDiskPage [ vfd ] [ i ];
// if page not in use, skip it
if ( off < 0 ) continue;
// check this now too
int32_t storedvfd;
readFromCache ( &storedvfd,
off ,
OFF_VFD,
sizeof(int32_t) );
if ( storedvfd != vfd ) { char *xx=NULL;*xx=0; }
// ensure we are in sync with the map of diskpage to mem
int32_t storedDiskPageNum;
readFromCache ( &storedDiskPageNum ,
off ,
OFF_DISKPAGENUM,
sizeof(int32_t) );
if ( storedDiskPageNum != i ) { char *xx=NULL;*xx=0; }
}
}
return true;
}
#include "BigFile.h"
#include "Threads.h"
bool DiskPageCache::verifyData ( BigFile *f ) {
int32_t vfd = f->getVfd();
// ensure validity
if ( vfd < 0 ) return true;
// this vfd may have already been nuked by call to unlink!
if ( ! m_memOffFromDiskPage [ vfd ] ) return true;
// debug msg
//log("VERIFYING PAGECACHE vfd=%"INT32" fn=%s",vfd,f->getFilename());
// read into here
char buf [ 32 * 1024 ];//GB_PAGE_SIZE ]; //m_diskPageSize ];
// ensure threads disabled
bool on = ! g_threads.areThreadsDisabled();
if ( on ) g_threads.disableThreads();
// disable ourselves
disableCache();
// add valid offsets used by vfd into m_availMemOff
for ( int32_t i = 0 ; i < m_maxPagesInFile [ vfd ] ; i++ ) {
int32_t off = m_memOffFromDiskPage [ vfd ] [ i ];
// if page not in use, skip it
if ( off < 0 ) continue;
// ensure we are in sync with the map of diskpage to mem
int32_t storedDiskPageNum;
readFromCache ( &storedDiskPageNum ,
off ,
OFF_DISKPAGENUM,
sizeof(int32_t) );
if ( storedDiskPageNum != i ) { char *xx=NULL;*xx=0; }
// check this now too
int32_t storedvfd;
readFromCache ( &storedvfd,
off ,
OFF_VFD,
sizeof(int32_t) );
if ( storedvfd != vfd ) { char *xx=NULL;*xx=0; }
//char *p = getMemPtrFromMemOff ( off );
int32_t size = 0;
readFromCache(&size, off, OFF_SIZE, sizeof(int32_t));
//int32_t size = *(int32_t *)(p+OFF_SIZE);
int32_t skip = 0;
readFromCache(&skip, off, OFF_SKIP, sizeof(int32_t));
if ( size > 32 * 1024 ){
char *xx=NULL; *xx=0; }
//int32_t skip = *(int32_t *)(p+OFF_SKIP);
FileState fstate;
if ( ! f->read ( buf ,
size ,
((int64_t)i * (int64_t)m_diskPageSize) +
(int64_t)skip ,
&fstate ,
NULL , // state
NULL , // callback
0 )){// niceness
// core if it did not complete
char *xx = NULL; *xx = 0; }
// compare to what we have in mem
log("checking vfd=%"INT32" "
"diskpage # %"INT32" size=%"INT32" skip=%"INT32""
, (int32_t)vfd , i, size, skip);
char buf2[32 * 1024];
readFromCache( buf2, off, HEADERSIZE + skip, size );
if ( memcmp ( buf, buf2, size ) != 0 ){
char *xx = NULL; *xx = 0; }
//if ( memcmp ( buf , p + HEADERSIZE + skip, size ) != 0 ) {
//char *xx = NULL; *xx = 0; }
}
if ( on ) g_threads.enableThreads();
enableCache();
// debug msg
log("DONE VERIFYING PAGECACHE");
return true;
}
// bigOff is used to get the MemPtr, smallOff is the offset in the Mem
void DiskPageCache::writeToCache( int32_t memOff,
int32_t memPageOff ,
void *inBuf,
int32_t size ){
/*
#ifdef GBUSESHM
if ( m_useSHM ) {
// what page are we on?
int32_t page = ( bigOff + smallOff ) / m_maxAllocSize;
// offset within that page
int32_t poff = ( bigOff + smallOff ) % m_maxAllocSize;
// sanity check
if ( page >= m_numShmids ) { char *xx=NULL; *xx=0; }
// sanity check
if ( poff + size > m_shmidSize[page] ) { char *xx=NULL;*xx=0; }
// get first byte
int shmid = m_shmids[page];
// assume we already have it loaded in
char *mem = s_mem;
// . is this the page we currently have loaded?
// . th shmdt and shmat() seems to take about 12 microseconds
// on avg to execute. so about 100 times per milliseconds.
// . seems like the writeToCache() is 3x slower than the
// readFromCache() perhaps because the dirty pages are
// COPIED back into system mem?
if ( shmid != s_shmid ) {
// time it
//int64_t start = gettimeofdayInMicroseconds();
// free current i guess
if ( s_mem && shmdt ( s_mem ) == -1 ) {
log("disk: shmdt: %s",mstrerror(errno));
char *xx=NULL;*xx=0;
}
// load it in if not
mem = (char *) shmat ( shmid , NULL, SHM_R|SHM_W );
// if this happens at startup, try calling shmat
// when we init this page cache above...
if ( mem == (char *)-1 ) {
log("disk: shmat: %s",mstrerror(errno));
char *xx=NULL;*xx=0;
}
// store it
s_mem = mem;
s_shmid = shmid;
// time it
//int64_t took = gettimeofdayInMicroseconds() -start;
//if ( took > 1 )
// logf(LOG_DEBUG,"disk: took %"INT64" us to write "
// "to shm page cache shmid=%"INT32".",took,
// (int32_t)shmid);
}
// store it into the cache
gbmemcpy ( mem + poff , inBuf , size );
return;
}
#endif
if ( m_useRAMDisk ){
int32_t numBytesWritten = pwrite( m_ramfd, inBuf, size,
bigOff + smallOff );
if ( numBytesWritten != size ){
char *xx=NULL; *xx=0;
}
return;
}
*/
char *p = getMemPtrFromMemOff ( memOff );
gbmemcpy(p + memPageOff, inBuf, size);
}
// . store cached disk info into "outBuf". up to "size" bytes of it.
void DiskPageCache::readFromCache( void *outBuf,
int32_t memOff,
int32_t pageOffset,
int32_t bytesToCopy ) {
/*
#ifdef GBUSESHM
if ( m_useSHM ) {
// what page are we on?
int32_t page = ( bigOff + smallOff ) / m_maxAllocSize;
// offset within that page
int32_t poff = ( bigOff + smallOff ) % m_maxAllocSize;
// sanity check
if ( page >= m_numShmids ) { char *xx=NULL; *xx=0; }
// sanity check
if ( poff + size > m_shmidSize[page] ) { char *xx=NULL;*xx=0; }
// get first byte
int shmid = m_shmids[page];
// assume we already have it loaded in
char *mem = s_mem;
// . is this the page we currently have loaded?
// . the shmdt() and shmat() seems to take about 2 MICROSECONDS
// on avg to execute here. about 3x faster than the
// writeToCache() above.
if ( shmid != s_shmid ) {
// time it
//int64_t start = gettimeofdayInMilliseconds();
// free current first so shmat has some room?
if ( s_mem && shmdt ( s_mem ) == -1 ) {
log("disk: shmdt: %s",mstrerror(errno));
char *xx=NULL;*xx=0;
}
// load it in if not
mem = (char *) shmat ( shmid , NULL, SHM_R|SHM_W );
// if this happens at startup, try calling shmat
// when we init this page cache above...
if ( mem == (char *)-1 ) {
log("disk: shmat: %s",mstrerror(errno));
char *xx=NULL;*xx=0;
}
// store it
s_mem = mem;
s_shmid = shmid;
// time it
//int64_t took = gettimeofdayInMilliseconds() -start;
//if ( took > 1 )
// logf(LOG_DEBUG,"disk: took %"INT64" ms to read "
// "to shm page cache shmid=%"INT32".",took,
// (int32_t)shmid);
}
// store it in outBuf
gbmemcpy ( outBuf , mem + poff , size );
return;
}
#endif
if ( m_useRAMDisk ) {
int32_t numBytesRead = pread( m_ramfd, outBuf, size,
bigOff + smallOff );
if ( numBytesRead != size ){
char *xx=NULL; *xx=0;
}
return;
}
*/
// the old fashioned way
char *p = getMemPtrFromMemOff ( memOff );
gbmemcpy(outBuf, p + pageOffset, bytesToCopy );
}
// lastly, we need some way to "force" a merge at around midnight when traffic
// is minimal, or when there are 3 or more indexdb files that are less than
// 80% in the indexdb disk page cache. because that means we are starting to
// do a lot of disk seeks.
// checks if indexdb needs merge
/*
bool DiskPageCache::needsMerge( ){
if ( !m_useRAMDisk ) return false;
int32_t numVfds = 0;
for ( int32_t i = 0; i < MAX_NUM_VFDS2; i++ ){
if ( !m_memOffFromDiskPage[i] ) continue;
// check to see if a file is less than 80% in the indexdb
// disk page cache
int32_t numOffsUsed = 0;
for ( int32_t j = 0; j < m_maxPagesInFile[i]; j++ ){
if ( m_memOffFromDiskPage[i][j] >= 0 )
numOffsUsed++;
}
if ( (numOffsUsed * 100)/m_maxPagesInFile[i] < 80 )
numVfds++;
}
if ( numVfds >= 3 )
return true;
return false;
}
*/
// 'ipcs -m' will show shared mem in linux
void freeAllSharedMem ( int32_t max ) {
// free shared mem whose pid no longer exists
//struct shmid_ds buf;
//shmctl ( 0 , SHM_STAT , &buf );
//int shmctl(int shmid, int cmd, struct shmid_ds *buf);
/*
#ifdef GBUSESHM
// types.h uses key_t type that shmget uses
// try to nuke it all
for ( int32_t i = 0 ; i < max ; i++ ) {
int shmid = i;
int32_t status = shmctl ( shmid , IPC_RMID , NULL);
if ( status == -1 ) {
//if ( errno != EINVAL )
// log("db: shctlt %"INT32": %s",(int32_t)shmid,mstrerror(errno));
}
else
log("db: Removed shmid %"INT32"",i);
}
#endif
*/
}
// types.h uses key_t type that shmget uses
#undef key_t