stasis-aries-wal/src/lladd/pageFile.c

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/**
@file
This file handles all of the file I/O for pages.
*/
#include "page.h"
#include <lladd/bufferManager.h>
#include "pageFile.h"
#include <assert.h>
#include <lladd/logger/logger2.h>
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#include <lladd/truncation.h>
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#include <sys/types.h>
#include <sys/stat.h>
/** For O_DIRECT. It's unclear that this is the correct thing to #define, but it works under linux. */
#define __USE_GNU
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#include <fcntl.h>
#include <unistd.h>
/** Allows boostrapping of the header page. */
#include <lladd/operations/pageOperations.h>
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static int stable = -1;
static pthread_mutex_t stable_mutex;
/* static long myLseek(int f, long offset, int whence); */
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static long myLseekNoLock(int f, long offset, int whence);
static int oldOffset = -1;
void pageRead(Page *ret) {
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long pageoffset;
long offset;
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pageoffset = ret->id * PAGE_SIZE;
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pthread_mutex_lock(&stable_mutex);
if(oldOffset != pageoffset) {
offset = myLseekNoLock(stable, pageoffset, SEEK_SET);
assert(offset == pageoffset);
} else {
offset = oldOffset;
}
oldOffset = offset + PAGE_SIZE;
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assert(offset == pageoffset);
int read_size;
read_size = read(stable, ret->memAddr, PAGE_SIZE);
if(read_size != PAGE_SIZE) {
if (!read_size) { /* Past EOF... */
/* long fileSize = myLseekNoLock(stable, 0, SEEK_END);
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offset = myLseekNoLock(stable, pageoffset, SEEK_SET);
assert(offset == pageoffset); */
/* if(fileSize <= pageoffset) { */
memset(ret->memAddr, 0, PAGE_SIZE);
/* write(stable, ret->memAddr, PAGE_SIZE); */ /* all this does is extend the file..why would we bother doing that? :)
} */
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} else if(read_size == -1) {
perror("pageFile.c couldn't read");
fflush(NULL);
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abort();
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} else {
printf("pageFile.c readfile: read_size = %d, errno = %d\n", read_size, errno);
abort();
}
}
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pthread_mutex_unlock(&stable_mutex);
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}
/** @todo need to sync the page file to disk occasionally, so that the
dirty page table can be kept up to date. */
void pageWrite(Page * ret) {
/** If the page is clean, there's no reason to write it out. */
if(!dirtyPages_isDirty(ret)) {
DEBUG(" =^)~ ");
return;
}
long pageoffset = ret->id * PAGE_SIZE;
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long offset ;
/* assert(ret->pending == 0); */
// If necessary, force the log to disk so that ret's LSN will be stable.
LogForce(pageReadLSN(ret));
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pthread_mutex_lock(&stable_mutex);
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if(oldOffset != pageoffset) {
offset = myLseekNoLock(stable, pageoffset, SEEK_SET);
assert(offset == pageoffset);
} else {
offset = oldOffset;
}
oldOffset = offset + PAGE_SIZE;
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assert(ret->memAddr);
/* DEBUG("Writing page %d\n", ret->id); */
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int write_ret = write(stable, ret->memAddr, PAGE_SIZE);
if(write_ret != PAGE_SIZE) {
if(-1 == write_ret) {
perror("pageFile.c couldn't write");
fflush(NULL);
abort();
} else if(0 == write_ret) {
/* now what? */
printf("write_ret is zero\n");
fflush(NULL);
abort();
} else {
printf("write_ret is %d\n", write_ret);
fflush(NULL);
abort();
}
}
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dirtyPages_remove(ret);
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pthread_mutex_unlock(&stable_mutex);
}
/** @todo O_DIRECT is broken in older linuxes (eg 2.4). The build script should disable it on such platforms. */
void openPageFile() {
DEBUG("Opening storefile.\n");
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stable = open (STORE_FILE, O_CREAT | O_RDWR | O_DIRECT, S_IRWXU | S_IRWXG | S_IRWXO);
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if(stable == -1) {
perror("couldn't open storefile");
fflush(NULL);
abort();
}
pthread_mutex_init(&stable_mutex, NULL);
}
void closePageFile() {
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int ret = close(stable);
if(-1 == ret) {
perror("Couldn't close storefile.");
fflush(NULL);
abort();
}
stable = -1;
}
static long myLseek(int f, long offset, int whence) {
long ret;
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pthread_mutex_lock(&stable_mutex);
ret = myLseekNoLock(f, offset, whence);
pthread_mutex_unlock(&stable_mutex);
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return ret;
}
static long myLseekNoLock(int f, long offset, int whence) {
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assert(! ( offset % 4096 ));
long ret = lseek(f, offset, whence);
if(ret == -1) {
perror("Couldn't seek.");
fflush(NULL);
abort();
}
return ret;
}
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/*void myFwrite(const void * dat, long size, FILE * f) {
int nmemb = fwrite(dat, size, 1, f);
/ * test * /
if(nmemb != 1) {
perror("myFwrite");
abort();
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/ * return FILE_WRITE_OPEN_ERROR; * /
}
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}*/
long pageCount() {
pthread_mutex_lock(&stable_mutex);
printf(".");
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long fileSize = myLseek(stable, 0, SEEK_END);
oldOffset = -1;
pthread_mutex_unlock(&stable_mutex);
assert(! (fileSize % PAGE_SIZE));
return fileSize / PAGE_SIZE;
}