Log truncation. (But no checkpoints, so it doesn't get called... it does pass testing though. :)

This commit is contained in:
Sears Russell 2004-07-01 00:53:36 +00:00
parent af152bd08e
commit 3349dbc6dc
7 changed files with 236 additions and 143 deletions

View file

@ -59,6 +59,7 @@ terms specified in this license.
/*#define DEBUG 1*/
#define LOG_FILE "logfile.txt"
#define LOG_FILE_SCRATCH "logfile.txt~"
#define STORE_FILE "storefile.txt"
#define BLOB0_FILE "blob0_file.txt"
#define BLOB1_FILE "blob1_file.txt"

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@ -1,126 +0,0 @@
/*---
This software is copyrighted by the Regents of the University of
California, and other parties. The following terms apply to all files
associated with the software unless explicitly disclaimed in
individual files.
The authors hereby grant permission to use, copy, modify, distribute,
and license this software and its documentation for any purpose,
provided that existing copyright notices are retained in all copies
and that this notice is included verbatim in any distributions. No
written agreement, license, or royalty fee is required for any of the
authorized uses. Modifications to this software may be copyrighted by
their authors and need not follow the licensing terms described here,
provided that the new terms are clearly indicated on the first page of
each file where they apply.
IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY
FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
ARISING OUT OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION, OR ANY
DERIVATIVES THEREOF, EVEN IF THE AUTHORS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND
NON-INFRINGEMENT. THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, AND
THE AUTHORS AND DISTRIBUTORS HAVE NO OBLIGATION TO PROVIDE
MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
GOVERNMENT USE: If you are acquiring this software on behalf of the
U.S. government, the Government shall have only "Restricted Rights" in
the software and related documentation as defined in the Federal
Acquisition Regulations (FARs) in Clause 52.227.19 (c) (2). If you are
acquiring the software on behalf of the Department of Defense, the
software shall be classified as "Commercial Computer Software" and the
Government shall have only "Restricted Rights" as defined in Clause
252.227-7013 (c) (1) of DFARs. Notwithstanding the foregoing, the
authors grant the U.S. Government and others acting in its behalf
permission to use and distribute the software in accordance with the
terms specified in this license.
---*/
/**
* @file
*
* External interaface to Logging API. (Only exposes operations used
* to add entries to the log.)
*
* Logger is the front end for logging actions -- whatever must be done (ie
* write to the log tail; flushing for commits) is handled in these functions
*
* @deprecated
* @see logger2.h
*
* @ingroup LLADD_CORE
* $Id$
*
* *************/
#ifndef __LOGGER_H__
#define __LOGGER_H__
#include "transactional.h"
#include "operations.h"
/**
Does NOT write a transaction begin; rather, just returns that the
LSN of a potential entry is -1 so the next command will have a
prevLSN of -1. (Althoug this is currently a no-op, it's possible
that some other logging scheme would actually write begin records.)
*/
long LogTransBegin(Transaction t);
/**
* logs the fact that a rid has been allocated for a transaction
*/
long LogTransAlloc(long prevLSN, int xid, recordid rid);
/**
Write a transaction COMMIT to the log tail, then flush the log tail immediately to disk
@return the LSN of this entry
*/
long LogTransCommit(long prevLSN, int xid);
/**
Write a transaction ABORTto the log tail
@return returns the LSN of this entry
*/
long LogTransAbort(long prevLSN, int xid);
/**
LogUpdate writes an UPDATE log record to the log tail
returns the LSN of this entry
*/
long LogUpdate (long prevLSN, int xid, recordid rid, Operation op, const void *args);
/**
Write a compensation log record. These records are used to allow
for efficient recovery, and possibly for log truncation. They
record the completion of undo operations.
*/
long LogCLR (long prevLSN, int xid, long ulLSN, recordid ulRID, long ulPrevLSN);
/**
Write a end transaction record @ todo What does this do exactly? Indicate completion of aborts?
*/
long LogEnd (long prevLSN, int xid);
/*
Starts a new log stream, possibly other stuff can go here too?
*/
void logInit();
/*
Called when ALL transactions are guaranteed to be completed (either
committed or aborted) and no new ones can be had. So therefore we
can close the log streamer and delete the log file. @todo Doesn't
delete logs right now. (For debugging)
*/
void logDeinit();
#endif

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@ -108,6 +108,41 @@ void syncLog();
*/
lsn_t flushedLSN();
/**
Truncates the log file. In the single-threaded case, this works as
follows:
First, the LSN passed to this function, minus sizeof(lsn_t) is
written to a new file, called logfile.txt~. (If logfile.txt~
already exists, then it is truncated.)
Next, the contents of the log, starting with the LSN passed into
this function are copied to logfile.txt~
Finally, logfile.txt~ is moved on top of logfile.txt
As long as the move system call is atomic, this function should
maintain the system's durability.
The multithreaded case is a bit more complicated, as we need
to deal with latching:
With no lock, copy the log. Upon completion, if the log has grown,
then copy the part that remains. Next, obtain a read/write latch
on the logfile, and copy any remaining portions of the log.
Perform the move, and release the latch.
*/
int truncateLog(lsn_t);
/**
@return The LSN of the first entry in the log file. (If the file
is empty, this returns the LSN of the log entry that would be
created if writeLogEntry were called.)
*/
lsn_t firstLogEntry();
/**
Close the log stream
*/

View file

@ -54,7 +54,10 @@ static void set_offsets(LogHandle * h, LogEntry * e, lsn_t lastRead);
/*-------------------------------------------------------*/
LogHandle getLogHandle() {
return getGuardedHandle(sizeof(lsn_t), NULL, NULL);
lsn_t lsn = firstLogEntry();
return getGuardedHandle(lsn, NULL, NULL);
}
LogHandle getLSNHandle(lsn_t lsn) {

View file

@ -43,7 +43,7 @@ terms specified in this license.
#include <lladd/logger/logHandle.h>
#include <assert.h>
#include <config.h>
#include <stdlib.h>
#include <malloc.h>
#include <unistd.h>
/**
@ -71,10 +71,14 @@ static lsn_t nextAvailableLSN = 0;
static int writeLogEntryIsReady = 0;
static lsn_t maxLSNEncountered = sizeof(lsn_t);
static lsn_t global_offset;
/**
@todo Put myFseek, myFwrite in their own file, and make a header for it... */
void myFwrite(const void * dat, size_t size, FILE * f);
long myFseek(FILE * f, long offset, int whence);
int openLogWriter() {
log = fopen(LOG_FILE, "a+");
if (log==NULL) {
@ -110,6 +114,12 @@ int openLogWriter() {
assert(0);
return FILE_WRITE_OPEN_ERROR;
}
global_offset = 0;
} else {
int count;
myFseek(log, 0, SEEK_SET);
count = fread(&global_offset, sizeof(lsn_t), 1, log);
assert(count == 1);
}
return 0;
@ -144,11 +154,18 @@ int writeLogEntry(LogEntry * e) {
}
if(!writeLogEntryIsReady) {
LogHandle lh = getLSNHandle(maxLSNEncountered);
LogHandle lh;
LogEntry * le;
assert(maxLSNEncountered >= sizeof(lsn_t));
lh = getLSNHandle(maxLSNEncountered);
nextAvailableLSN = maxLSNEncountered;
while((le = nextInLog(&lh))) {
nextAvailableLSN = le->LSN + sizeofLogEntry(le) + sizeof(lsn_t);
nextAvailableLSN = le->LSN + sizeofLogEntry(le) + sizeof(size_t);;
free(le);
}
writeLogEntryIsReady = 1;
}
@ -156,8 +173,20 @@ int writeLogEntry(LogEntry * e) {
/* Set the log entry's LSN. */
#ifdef DEBUGGING
fseek(log, 0, SEEK_END);
e->LSN = ftell(log);
if(nextAvailableLSN != e->LSN) {
assert(nextAvailableLSN <= e->LSN);
DEBUG("Detected log truncation: nextAvailableLSN = %ld, but log length is %ld.\n", (long)nextAvailableLSN, e->LSN);
}
#endif
e->LSN = nextAvailableLSN;
fseek(log, nextAvailableLSN - global_offset, SEEK_SET);
nextAvailableLSN += (size + sizeof(size_t));
/* Print out the size of this log entry. (not including this item.) */
nmemb = fwrite(&size, sizeof(size_t), 1, log);
@ -272,8 +301,93 @@ LogEntry * readLSNEntry(lsn_t LSN) {
}
}
fseek(log, LSN, SEEK_SET);
fseek(log, LSN - global_offset, SEEK_SET);
ret = readLogEntry();
return ret;
}
int truncateLog(lsn_t LSN) {
FILE *tmpLog = fopen(LOG_FILE_SCRATCH, "w+"); /* w+ = truncate, and open for writing. */
LogEntry * le;
LogHandle lh;
long size;
int count;
if (tmpLog==NULL) {
assert(0);
/*there was an error opening this file */
perror("logTruncate() couldn't create scratch log file!");
return FILE_WRITE_OPEN_ERROR;
}
/* Need to write LSN - sizeof(lsn_t) to make room for the offset in
the file. If we truncate to lsn 10, we'll put lsn 10 in position
4, so the file offset is 6. */
LSN -= sizeof(lsn_t);
DEBUG("Truncate(%ld) new file offset = %ld\n", LSN + sizeof(lsn_t), LSN);
myFwrite(&LSN, sizeof(lsn_t), tmpLog);
LSN += sizeof(lsn_t);
lh = getLSNHandle(LSN);
while((le = nextInLog(&lh))) {
size = sizeofLogEntry(le);
myFwrite(&size, sizeof(lsn_t), tmpLog);
myFwrite(le, size, tmpLog);
free (le);
}
fflush(tmpLog);
#ifdef HAVE_FDATASYNC
fdatasync(fileno(tmpLog));
#else
fsync(fileno(tmpLog));
#endif
fclose(log); /* closeLogWriter calls sync, but we don't need to. :) */
fclose(tmpLog);
if(rename(LOG_FILE_SCRATCH, LOG_FILE)) {
perror("Log truncation failed!");
abort();
}
log = fopen(LOG_FILE, "a+");
if (log==NULL) {
abort();
/*there was an error opening this file */
return FILE_WRITE_OPEN_ERROR;
}
myFseek(log, 0, SEEK_SET);
count = fread(&global_offset, sizeof(lsn_t), 1, log);
assert(count == 1);
return 0;
}
lsn_t firstLogEntry() {
return global_offset + sizeof(lsn_t);
}
void myFwrite(const void * dat, size_t size, FILE * f) {
int nmemb = fwrite(dat, size, 1, f);
/* test */
if(nmemb != 1) {
perror("myFwrite");
abort();
/* return FILE_WRITE_OPEN_ERROR; */
}
}

View file

@ -47,6 +47,8 @@ terms specified in this license.
#include <lladd/logger/logHandle.h>
#include <lladd/transactional.h>
#include "../check_includes.h"
#define LOG_NAME "check_logWriter.log"
static void setup_log() {
@ -167,6 +169,66 @@ START_TEST(logHandleColdReverseIterator) {
}
END_TEST
/**
@test
Build a simple log, truncate it, and then test the logWriter routines against it.
*/
START_TEST(logWriterTruncate) {
LogEntry * le;
LogEntry * le2;
LogEntry * le3 = NULL;
LogEntry * tmp;
LogHandle lh = getLogHandle();
int i = 0;
setup_log();
while(i < 234) {
i++;
le = nextInLog(&lh);
}
le2 = nextInLog(&lh);
i = 0;
while(i < 23) {
i++;
le3 = nextInLog(&lh);
}
truncateLog(le->LSN);
tmp = readLSNEntry(le->LSN);
fail_unless(NULL != tmp, NULL);
fail_unless(tmp->LSN == le->LSN, NULL);
tmp = readLSNEntry(le2->LSN);
fail_unless(NULL != tmp, NULL);
fail_unless(tmp->LSN == le2->LSN, NULL);
tmp = readLSNEntry(le3->LSN);
fail_unless(NULL != tmp, NULL);
fail_unless(tmp->LSN == le3->LSN, NULL);
lh = getLogHandle();
i = 0;
while((le = nextInLog(&lh))) {
i++;
}
fail_unless(i == (3000 - 234 + 1), NULL);
} END_TEST
Suite * check_suite(void) {
Suite *s = suite_create("logWriter");
/* Begin a new test */
@ -176,9 +238,13 @@ Suite * check_suite(void) {
tcase_add_test(tc, logWriterTest);
tcase_add_test(tc, logHandleColdReverseIterator);
tcase_add_test(tc, logWriterTruncate);
/* --------------------------------------------- */
tcase_add_checked_fixture(tc, setup, teardown);
suite_add_tcase(s, tc);
return s;
}