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

/*---
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---*/
/*******************************
 * $Id$
 *
 * implementation of the page buffer
 * *************************************************/

#include <config.h>
#include <lladd/common.h>

#include <assert.h>
#include <stdio.h>

#include <lladd/bufferManager.h>
#include "blobManager.h"
#include <lladd/pageCache.h>
#include <lladd/logger/logWriter.h>

static FILE * stable = NULL;
static unsigned int lastFreepage = 0;

/* ** File I/O functions ** */
/* Defined in blobManager.c, but don't want to export this in any public .h files... */
long myFseek(FILE * f, long offset, int whence);

void pageRead(Page *ret) {
  long fileSize = myFseek(stable, 0, SEEK_END);
  long pageoffset = ret->id * PAGE_SIZE;
  long offset;

  DEBUG("Reading page %d\n", ret->id);

  if(!ret->memAddr) {
    ret->memAddr = malloc(PAGE_SIZE);
  }
  assert(ret->memAddr);
  
  if ((ret->id)*PAGE_SIZE >= fileSize) {
    myFseek(stable, (1+ ret->id) * PAGE_SIZE -1, SEEK_SET);
    if(1 != fwrite("", 1, 1, stable)) {
      if(feof(stable)) { printf("Unexpected eof extending storefile!\n"); fflush(NULL); abort(); }
      if(ferror(stable)) { printf("Error extending storefile! %d", ferror(stable)); fflush(NULL); abort(); }
    }

  }
  offset = myFseek(stable, pageoffset, SEEK_SET);
  assert(offset == pageoffset);

  if(1 != fread(ret->memAddr, PAGE_SIZE, 1, stable)) {
                                                                                                                 
    if(feof(stable)) { printf("Unexpected eof reading!\n"); fflush(NULL); abort(); }
    if(ferror(stable)) { printf("Error reading stream! %d", ferror(stable)); fflush(NULL); abort(); }
                                                                                                                 
  }

}

void pageWrite(const Page * ret) {

  long pageoffset = ret->id * PAGE_SIZE;
  long offset = myFseek(stable, pageoffset, SEEK_SET);
  assert(offset == pageoffset);
  assert(ret->memAddr);

  DEBUG("Writing page %d\n", ret->id);

  if(flushedLSN() < pageReadLSN(*ret)) {
    DEBUG("pageWrite is calling syncLog()!\n");
    syncLog();
  }

  if(1 != fwrite(ret->memAddr, PAGE_SIZE, 1, stable)) {
                                                                                                                 
    if(feof(stable)) { printf("Unexpected eof writing!\n"); fflush(NULL); abort(); }
    if(ferror(stable)) { printf("Error writing stream! %d", ferror(stable)); fflush(NULL); abort(); }
                                                                                                                 
  }


}

static void openPageFile() {

  DEBUG("Opening storefile.\n");
  if( ! (stable = fopen(STORE_FILE, "r+"))) { /* file may not exist */
    byte* zero = calloc(1, PAGE_SIZE);

    if(!(stable = fopen(STORE_FILE, "w+"))) { perror("Couldn't open or create store file"); abort(); }

    /* Write out one page worth of zeros to get started. */
    
    if(1 != fwrite(zero, PAGE_SIZE, 1, stable)) { assert (0); }

    free(zero);
  }
  
  lastFreepage = 0;
  DEBUG("storefile opened.\n");

}
static void closePageFile() {

  int ret = fclose(stable);
  assert(!ret);
  stable = NULL;
}

/* void pageMap(Page *ret) {
  pageRead(ret);
}
int flushPage(Page ret) {
  pageWrite(&ret);
  return 0;
  } */

/*
void pageMap(Page *ret) {

	int fileSize;
	/ * this was lseek(stable, SEEK_SET, pageid*PAGE_SIZE), but changed to
	            lseek(stable, pageid*PAGE_SIZE, SEEK_SET) by jkit (Wed Mar 24 12:59:18 PST 2004)* /
	fileSize = lseek(stable, 0, SEEK_END);

	if ((ret->id)*PAGE_SIZE >= fileSize) {
		lseek(stable, (1 + ret->id)*PAGE_SIZE -1 , SEEK_SET);
		write(stable, "", 1);
	}

	if((ret->memAddr = mmap((void *) 0, PAGE_SIZE, (PROT_READ | PROT_WRITE), MAP_SHARED, stable, (ret->id)*PAGE_SIZE)) == (void*)-1) {
		printf("ERROR: %i on %s line %d", errno, __FILE__, __LINE__);
		exit(errno);
	}
}

int flushPage(Page page) {

	if( munmap(page.memAddr, PAGE_SIZE) )
		return MEM_WRITE_ERROR;

	return 0;
}

*/

int bufInit() {

	stable = NULL;

	/* Create STORE_FILE, if necessary, then open it read/write 

	   If we're creating it, then put one all-zero record at the beginning of it.  
	   (Need to have at least one record in the PAGE file?)

	   It used to be that there was one file per page, and LSN needed to be set to -1.  

	   Now, zero means uninitialized, so this could probably be replaced 
	   with a call to open(... O_CREAT|O_RW) or something like that...
	*/
	/*	if( (stable = open(STORE_FILE, O_RDWR, 0)) == -1 ) { / * file may not exist * /
		void *zero = mmap(0, PAGE_SIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0); / * zero = /dev/zero * /
		if( (stable = creat(STORE_FILE, 0666)) == -1 ) { / * cannot even create it * /
			printf("ERROR: %i on %s line %d", errno, __FILE__, __LINE__);
			exit(errno);
		}
		/ * kick off a fresh page * /
		if( write(stable, zero, PAGE_SIZE) != PAGE_SIZE ) { / * write zeros out * /
			printf("ERROR: %i on %s line %d", errno, __FILE__, __LINE__);
			exit(errno);
		}
		if( close(stable) || ((stable = open(STORE_FILE, O_RDWR, 0)) == -1) ) { / * need to reopen with read perms * /
			printf("ERROR: %i on %s line %d", errno, __FILE__, __LINE__);
			exit(errno);
		}
	} */

	openPageFile();
	pageCacheInit();
	openBlobStore();
	
	return 0;
}

void bufDeinit() {

	closeBlobStore();
	pageCacheDeinit();
	closePageFile();
	/*	if( close(stable) ) {
		printf("ERROR: %i on %s line %d", errno, __FILE__, __LINE__);
		exit(errno);
		}*/

	return;
}
/**
    Just close file descriptors, don't do any other clean up. (For
    testing.)
*/
void simulateBufferManagerCrash() {
  closeBlobStore();
  closePageFile();
  /*  close(stable);
      stable = -1;*/

}

/* ** No file I/O below this line. ** */

Page loadPage (int pageid) {
	return *loadPagePtr(pageid);
}

Page * lastRallocPage = 0;


recordid ralloc(int xid, /*lsn_t lsn,*/ long size) {

  recordid ret;
  Page p;

  DEBUG("Rallocing blob of size %ld\n", (long int)size);

  assert(size < BLOB_THRESHOLD_SIZE || size == BLOB_SLOT);

  /*  if (size >= BLOB_THRESHOLD_SIZE) { 
    
    ret = allocBlob(xid, lsn, size);

    } else { */
  
    while(freespace(p = loadPage(lastFreepage)) < size ) { lastFreepage++; }
    ret = pageRalloc(p, size);
    
    /*  }  */
  DEBUG("alloced rid = {%d, %d, %ld}\n", ret.page, ret.slot, ret.size);
  return ret;
}
long readLSN(int pageid) {

	return pageReadLSN(loadPage(pageid));
}
/*
static void writeLSN(lsn_t LSN, int pageid) {
	Page *p = loadPagePtr(pageid);
	p->LSN = LSN;
	pageWriteLSN(*p);
	}*/
void writeRecord(int xid, lsn_t lsn, recordid rid, const void *dat) {

	Page *p;

	if(rid.size > BLOB_THRESHOLD_SIZE) {
	  DEBUG("Writing blob.\n");
	  writeBlob(xid, lsn, rid, dat);

	} else {
	  DEBUG("Writing record.\n");
	  p = loadPagePtr(rid.page);
	  assert( (p->id == rid.page) && (p->memAddr != NULL) );	
	  /** @todo This assert should be here, but the tests are broken, so it causes bogus failures. */
	  /*assert(pageReadLSN(*p) <= lsn);*/
	  
	  pageWriteRecord(xid, *p, rid, dat);
	  /*	  writeLSN(lsn, rid.page); */
	  p->LSN = lsn;
	  pageWriteLSN(*p);
	}
}
void readRecord(int xid, recordid rid, void *buf) {
  if(rid.size > BLOB_THRESHOLD_SIZE) {
    DEBUG("Reading blob. xid = %d rid = { %d %d %ld } buf = %x\n", xid, rid.page, rid.slot, rid.size, (unsigned int)buf);
    readBlob(xid, rid, buf);
  } else {
    DEBUG("Reading record xid = %d rid = { %d %d %ld } buf = %x\n", xid, rid.page, rid.slot, rid.size, (unsigned int)buf);
    pageReadRecord(xid, loadPage(rid.page), rid, buf);
  }
}

int bufTransCommit(int xid, lsn_t lsn) {

  commitBlobs(xid);
  pageCommit(xid);

  return 0;
}

int bufTransAbort(int xid, lsn_t lsn) {

  abortBlobs(xid);  /* abortBlobs doesn't write any log entries, so it doesn't need the lsn. */
  pageAbort(xid);

  return 0;
}