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foundationdb/fdbserver/DiskQueue.actor.cpp

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/*
* DiskQueue.actor.cpp
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2013-2022 Apple Inc. and the FoundationDB project authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "fdbserver/IDiskQueue.h"
#include "flow/IAsyncFile.h"
#include "fdbserver/Knobs.h"
#include "fdbrpc/simulator.h"
#include "crc32/crc32c.h"
#include "flow/genericactors.actor.h"
#include "flow/xxhash.h"
#include "flow/actorcompiler.h" // This must be the last #include.
typedef bool (*compare_pages)(void*, void*);
typedef int64_t loc_t;
// 0 -> 0
// 1 -> 4k
// 4k -> 4k
int64_t pageCeiling(int64_t loc) {
return (loc + _PAGE_SIZE - 1) / _PAGE_SIZE * _PAGE_SIZE;
}
// 0 -> 0
// 1 -> 0
// 4k -> 4k
int64_t pageFloor(int64_t loc) {
return loc / _PAGE_SIZE * _PAGE_SIZE;
}
struct StringBuffer {
Standalone<StringRef> str;
int reserved;
UID id;
StringBuffer(UID fromFileID) : reserved(0), id(fromFileID) {}
int size() const { return str.size(); }
Standalone<StringRef> get() { return str; }
void clear() {
str = Standalone<StringRef>();
reserved = 0;
}
void clearReserve(int size) {
str = Standalone<StringRef>();
reserved = size;
str.contents() = StringRef(new (str.arena()) uint8_t[size], 0);
}
void append(StringRef x) { memcpy(append(x.size()), x.begin(), x.size()); }
void* append(int bytes) {
ASSERT(str.size() + bytes <= reserved);
void* p = const_cast<uint8_t*>(str.end());
str.contents() = StringRef(str.begin(), str.size() + bytes);
return p;
}
StringRef pop_front(int bytes) {
ASSERT(bytes <= str.size());
StringRef result = str.substr(0, bytes);
str.contents() = str.substr(bytes);
return result;
}
void alignReserve(int alignment, int size) {
ASSERT(alignment && (alignment & (alignment - 1)) == 0); // alignment is a power of two
if (size >= reserved) {
// SOMEDAY: Use a new arena and discard the old one after copying?
reserved = std::max(size, reserved * 2);
if (reserved > 1e9) {
printf("WOAH! Huge allocation\n");
TraceEvent(SevError, "StringBufferHugeAllocation", id)
.detail("Alignment", alignment)
.detail("Reserved", reserved)
.backtrace();
}
uint8_t* b = new (str.arena()) uint8_t[reserved + alignment - 1];
uint8_t* e = b + (reserved + alignment - 1);
uint8_t* p = (uint8_t*)(int64_t(b + alignment - 1) &
~(alignment - 1)); // first multiple of alignment greater than or equal to b
ASSERT(p >= b && p + reserved <= e && int64_t(p) % alignment == 0);
if (str.size() > 0) {
memcpy(p, str.begin(), str.size());
}
str.contents() = StringRef(p, str.size());
}
}
};
struct SyncQueue : ReferenceCounted<SyncQueue> {
SyncQueue(int outstandingLimit, Reference<IAsyncFile> file) : outstandingLimit(outstandingLimit), file(file) {
for (int i = 0; i < outstandingLimit; i++)
outstanding.push_back(Void());
}
Future<Void> onSync() { // Future is set when all writes completed before the call to onSync are complete
if (outstanding.size() <= outstandingLimit)
outstanding.push_back(waitAndSync(this));
return outstanding.back();
}
private:
int outstandingLimit;
Deque<Future<Void>> outstanding;
Reference<IAsyncFile> file;
ACTOR static Future<Void> waitAndSync(SyncQueue* self) {
wait(self->outstanding.front());
self->outstanding.pop_front();
wait(self->file->sync());
return Void();
}
};
// We use a Tracked instead of a Reference when the shutdown/destructor code would need to wait() on pending file
// operations (e.g., read).
template <typename T>
class Tracked {
protected:
struct TrackMe : NonCopyable {
T* self;
explicit TrackMe(T* self) : self(self) {
self->actorCount++;
if (self->actorCount == 1)
self->actorCountIsZero.set(false);
}
~TrackMe() {
self->actorCount--;
if (self->actorCount == 0)
self->actorCountIsZero.set(true);
}
};
Future<Void> onSafeToDestruct() {
if (actorCountIsZero.get()) {
return Void();
} else {
return actorCountIsZero.onChange();
}
}
private:
int actorCount = 0;
AsyncVar<bool> actorCountIsZero = true;
};
// DiskQueue uses two files to implement a dynamically resizable ring buffer, where files only allow append and read
// operations.
// To increase the ring buffer size, it creates a ring buffer in the other file.
// After finish reading the current file, it switch to use the other file as the ring buffer.
class RawDiskQueue_TwoFiles : public Tracked<RawDiskQueue_TwoFiles> {
public:
RawDiskQueue_TwoFiles(std::string basename, std::string fileExtension, UID dbgid, int64_t fileSizeWarningLimit)
: basename(basename), fileExtension(fileExtension), dbgid(dbgid), dbg_file0BeginSeq(0),
fileSizeWarningLimit(fileSizeWarningLimit), onError(delayed(error.getFuture())), onStopped(stopped.getFuture()),
readyToPush(Void()), lastCommit(Void()), isFirstCommit(true), readingBuffer(dbgid), readingFile(-1),
readingPage(-1), writingPos(-1), fileExtensionBytes(SERVER_KNOBS->DISK_QUEUE_FILE_EXTENSION_BYTES),
fileShrinkBytes(SERVER_KNOBS->DISK_QUEUE_FILE_SHRINK_BYTES) {
if (BUGGIFY)
fileExtensionBytes = _PAGE_SIZE * deterministicRandom()->randomSkewedUInt32(1, 10 << 10);
if (BUGGIFY)
fileShrinkBytes = _PAGE_SIZE * deterministicRandom()->randomSkewedUInt32(1, 10 << 10);
files[0].dbgFilename = filename(0);
files[1].dbgFilename = filename(1);
// We issue reads into firstPages, so it needs to be 4k aligned.
firstPages.reserve(firstPages.arena(), 2);
void* pageMemory = operator new(sizeof(Page) * 3, firstPages.arena());
// firstPages is assumed to always be a valid page, and our initialization here is the only
// time that it would not contain a valid page. Whenever DiskQueue reaches in to look at
// these bytes, it only cares about `seq`, and having that be all 0xFF's means uninitialized
// pages will look like the ultimate end of the disk queue, rather than the beginning of it.
// This makes code fail in more immediate and obvious ways.
firstPages[0] = (Page*)((((uintptr_t)pageMemory + 4095) / 4096) * 4096);
memset(firstPages[0], 0xFF, sizeof(Page));
firstPages[1] = (Page*)((uintptr_t)firstPages[0] + 4096);
memset(firstPages[1], 0xFF, sizeof(Page));
stallCount.init("RawDiskQueue.StallCount"_sr);
}
Future<Void> pushAndCommit(Standalone<StringRef> pageData, StringBuffer* pageMem, uint64_t poppedPages) {
return pushAndCommit(this, pageData, pageMem, poppedPages);
}
void stall() {
stallCount++;
readyToPush = lastCommit;
}
Future<Standalone<StringRef>> readFirstAndLastPages(compare_pages compare) {
return readFirstAndLastPages(this, compare);
}
void setStartPage(int file, int64_t page) {
TraceEvent("RDQSetStart", dbgid)
.detail("FileNum", file)
.detail("PageNum", page)
.detail("File0Name", files[0].dbgFilename);
readingFile = file;
readingPage = page;
}
Future<Void> setPoppedPage(int file, int64_t page, int64_t debugSeq) {
return setPoppedPage(this, file, page, debugSeq);
}
// FIXME: let the caller pass in where to write the data.
Future<Standalone<StringRef>> read(int file, int page, int nPages) { return read(this, file, page, nPages); }
Future<Standalone<StringRef>> readNextPage() { return readNextPage(this); }
Future<Void> truncateBeforeLastReadPage() { return truncateBeforeLastReadPage(this); }
Future<Void> getError() { return onError; }
Future<Void> onClosed() { return onStopped; }
void dispose() { shutdown(this, true); }
void close() { shutdown(this, false); }
StorageBytes getStorageBytes() const {
int64_t free;
int64_t total;
g_network->getDiskBytes(parentDirectory(basename), free, total);
return StorageBytes(free,
total,
files[0].size + files[1].size,
free); // TODO: we could potentially do better in the available field by accounting for the
// unused pages at the end of the file
}
// private:
struct Page {
uint8_t data[_PAGE_SIZE];
};
struct File {
Reference<IAsyncFile> f;
int64_t size; // always a multiple of _PAGE_SIZE, even if the physical file isn't for some reason
int64_t popped;
std::string dbgFilename;
Reference<SyncQueue> syncQueue;
File() : size(-1), popped(-1) {}
void setFile(Reference<IAsyncFile> f) {
this->f = f;
this->syncQueue = makeReference<SyncQueue>(1, f);
}
};
File files[2]; // After readFirstAndLastPages(), files[0] is logically before files[1] (pushes are always into
// files[1])
Standalone<VectorRef<Page*>> firstPages;
std::string basename;
std::string fileExtension;
std::string filename(int i) const { return basename + format("%d.%s", i, fileExtension.c_str()); }
UID dbgid;
int64_t dbg_file0BeginSeq;
int64_t fileSizeWarningLimit;
Promise<Void> error, stopped;
Future<Void> onError, onStopped;
Future<Void> readyToPush;
Future<Void> lastCommit;
bool isFirstCommit;
StringBuffer readingBuffer; // Pages that have been read and not yet returned
int readingFile; // File index where the next page (after readingBuffer) should be read from, i.e.,
// files[readingFile]. readingFile = 2 if recovery is complete (all files have been read).
int64_t readingPage; // Page within readingFile that is the next page after readingBuffer
int64_t writingPos; // Position within files[1] that will be next written
int64_t fileExtensionBytes;
int64_t fileShrinkBytes;
Int64MetricHandle stallCount;
Future<Void> truncateFile(int file, int64_t pos) { return truncateFile(this, file, pos); }
// FIXME: Merge this function with IAsyncFileSystem::incrementalDeleteFile().
ACTOR static void incrementalTruncate(Reference<IAsyncFile> file) {
state int64_t remainingFileSize = wait(file->size());
for (; remainingFileSize > 0; remainingFileSize -= FLOW_KNOBS->INCREMENTAL_DELETE_TRUNCATE_AMOUNT) {
wait(file->truncate(remainingFileSize));
wait(file->sync());
wait(delay(FLOW_KNOBS->INCREMENTAL_DELETE_INTERVAL));
}
TraceEvent("DiskQueueReplaceTruncateEnded").detail("Filename", file->getFilename());
}
#if defined(_WIN32)
ACTOR static Future<Reference<IAsyncFile>> replaceFile(Reference<IAsyncFile> toReplace) {
// Windows doesn't support a rename over an open file.
wait(toReplace->truncate(4 << 10));
return toReplace;
}
#else
ACTOR static Future<Reference<IAsyncFile>> replaceFile(Reference<IAsyncFile> toReplace) {
incrementalTruncate(toReplace);
Reference<IAsyncFile> _replacement = wait(IAsyncFileSystem::filesystem()->open(
toReplace->getFilename(),
IAsyncFile::OPEN_ATOMIC_WRITE_AND_CREATE | IAsyncFile::OPEN_CREATE | IAsyncFile::OPEN_READWRITE |
IAsyncFile::OPEN_UNCACHED | IAsyncFile::OPEN_UNBUFFERED | IAsyncFile::OPEN_LOCK,
0600));
state Reference<IAsyncFile> replacement = _replacement;
wait(replacement->sync());
return replacement;
}
#endif
Future<Future<Void>> push(Standalone<StringRef> pageData, std::vector<Reference<SyncQueue>>* toSync) {
return push(this, pageData, toSync);
}
ACTOR static UNCANCELLABLE Future<Future<Void>> push(RawDiskQueue_TwoFiles* self,
Standalone<StringRef> pageData,
std::vector<Reference<SyncQueue>>* toSync) {
// Write the given data (pageData) to the queue files, swapping or extending them if necessary.
// Don't do any syncs, but push the modified file(s) onto toSync.
ASSERT(self->readingFile == 2);
ASSERT(pageData.size() % _PAGE_SIZE == 0);
ASSERT(int64_t(pageData.begin()) % _PAGE_SIZE == 0);
ASSERT(self->writingPos % _PAGE_SIZE == 0);
ASSERT(self->files[0].size % _PAGE_SIZE == 0 && self->files[1].size % _PAGE_SIZE == 0);
state std::vector<Future<Void>> waitfor;
if (pageData.size() + self->writingPos > self->files[1].size) {
if (self->files[0].popped == self->files[0].size) {
// Finish self->files[1] and swap
int p = self->files[1].size - self->writingPos;
if (p > 0) {
toSync->push_back(self->files[1].syncQueue);
/*TraceEvent("RDQWriteAndSwap", this->dbgid).detail("File1name", self->files[1].dbgFilename).detail("File1size", self->files[1].size)
.detail("WritingPos", self->writingPos).detail("WritingBytes", p);*/
waitfor.push_back(uncancellable(
holdWhile(pageData, self->files[1].f->write(pageData.begin(), p, self->writingPos))));
pageData.contents() = pageData.substr(p);
}
self->dbg_file0BeginSeq += self->files[0].size;
std::swap(self->files[0], self->files[1]);
std::swap(self->firstPages[0], self->firstPages[1]);
self->files[1].popped = 0;
self->writingPos = 0;
*self->firstPages[1] = *(const Page*)pageData.begin();
const int64_t activeDataVolume = pageCeiling(self->files[0].size - self->files[0].popped +
self->fileExtensionBytes + self->fileShrinkBytes);
const int64_t desiredMaxFileSize =
pageCeiling(std::max(activeDataVolume, SERVER_KNOBS->TLOG_HARD_LIMIT_BYTES * 2));
const bool frivolouslyTruncate = BUGGIFY_WITH_PROB(0.1);
if (self->files[1].size > desiredMaxFileSize || frivolouslyTruncate) {
// Either shrink self->files[1] to the size of self->files[0], or chop off fileShrinkBytes
int64_t maxShrink =
pageFloor(std::max(self->files[1].size - desiredMaxFileSize, self->fileShrinkBytes));
if ((maxShrink > SERVER_KNOBS->DISK_QUEUE_MAX_TRUNCATE_BYTES) ||
(frivolouslyTruncate && deterministicRandom()->random01() < 0.3)) {
CODE_PROBE(true, "Replacing DiskQueue file");
TraceEvent("DiskQueueReplaceFile", self->dbgid)
.detail("Filename", self->files[1].f->getFilename())
.detail("OldFileSize", self->files[1].size)
.detail("ElidedTruncateSize", maxShrink);
Reference<IAsyncFile> newFile = wait(replaceFile(self->files[1].f));
self->files[1].setFile(newFile);
waitfor.push_back(self->files[1].f->truncate(self->fileExtensionBytes));
self->files[1].size = self->fileExtensionBytes;
} else {
CODE_PROBE(true, "Truncating DiskQueue file");
const int64_t startingSize = self->files[1].size;
self->files[1].size -= std::min(maxShrink, self->files[1].size);
self->files[1].size = std::max(self->files[1].size, self->fileExtensionBytes);
TraceEvent("DiskQueueTruncate", self->dbgid)
.detail("Filename", self->files[1].f->getFilename())
.detail("OldFileSize", startingSize)
.detail("NewFileSize", self->files[1].size);
waitfor.push_back(self->files[1].f->truncate(self->files[1].size));
}
}
} else {
// Extend self->files[1] to accomodate the new write and about 10MB or 2x current size for future
// writes.
/*TraceEvent("RDQExtend", this->dbgid).detail("File1name", self->files[1].dbgFilename).detail("File1size", self->files[1].size)
.detail("ExtensionBytes", fileExtensionBytes);*/
int64_t minExtension = pageData.size() + self->writingPos - self->files[1].size;
self->files[1].size += std::min(std::max(self->fileExtensionBytes, minExtension),
self->files[0].size + self->files[1].size + minExtension);
waitfor.push_back(self->files[1].f->truncate(self->files[1].size));
if (self->fileSizeWarningLimit > 0 && self->files[1].size > self->fileSizeWarningLimit) {
TraceEvent(SevWarnAlways, "DiskQueueFileTooLarge", self->dbgid)
.suppressFor(1.0)
.detail("Filename", self->filename(1))
.detail("Size", self->files[1].size);
}
}
} else if (self->writingPos == 0) {
// If this is the first write to a brand new disk queue file.
*self->firstPages[1] = *(const Page*)pageData.begin();
}
/*TraceEvent("RDQWrite", this->dbgid).detail("File1name", self->files[1].dbgFilename).detail("File1size", self->files[1].size)
.detail("WritingPos", self->writingPos).detail("WritingBytes", pageData.size());*/
self->files[1].size = std::max(self->files[1].size, self->writingPos + pageData.size());
toSync->push_back(self->files[1].syncQueue);
waitfor.push_back(uncancellable(
holdWhile(pageData, self->files[1].f->write(pageData.begin(), pageData.size(), self->writingPos))));
self->writingPos += pageData.size();
return waitForAllReadyThenThrow(waitfor);
}
// Write the given data (pageData) to the queue files of self, sync data to disk, and delete the memory (pageMem)
// that hold the pageData
ACTOR static UNCANCELLABLE Future<Void> pushAndCommit(RawDiskQueue_TwoFiles* self,
Standalone<StringRef> pageData,
StringBuffer* pageMem,
uint64_t poppedPages) {
state Promise<Void> pushing, committed;
state Promise<Void> errorPromise = self->error;
state std::string filename = self->files[0].dbgFilename;
state UID dbgid = self->dbgid;
state std::vector<Reference<SyncQueue>> syncFiles;
state Future<Void> lastCommit = self->lastCommit;
try {
// pushing might need to wait for previous pushes to start (to maintain order) or for
// a previous commit to finish if stall() was called
Future<Void> ready = self->readyToPush;
self->readyToPush = pushing.getFuture();
self->lastCommit = committed.getFuture();
// the first commit must complete before we can pipeline other commits so that we will always have a valid
// page to binary search to
if (self->isFirstCommit) {
self->isFirstCommit = false;
self->readyToPush = self->lastCommit;
}
wait(ready);
CODE_PROBE(pageData.size() > sizeof(Page), "push more than one page of data");
Future<Void> pushed = wait(self->push(pageData, &syncFiles));
pushing.send(Void());
ASSERT(syncFiles.size() >= 1 && syncFiles.size() <= 2);
CODE_PROBE(2 == syncFiles.size(), "push spans both files");
wait(pushed);
delete pageMem;
pageMem = 0;
Future<Void> sync = syncFiles[0]->onSync();
for (int i = 1; i < syncFiles.size(); i++)
sync = sync && syncFiles[i]->onSync();
wait(sync);
wait(lastCommit);
// Calling check_yield instead of yield to avoid a destruction ordering problem in simulation
if (g_network->check_yield(g_network->getCurrentTask())) {
wait(delay(0, g_network->getCurrentTask()));
}
self->updatePopped(poppedPages * sizeof(Page));
/*TraceEvent("RDQCommitEnd", self->dbgid).detail("DeltaPopped", poppedPages*sizeof(Page)).detail("PoppedCommitted", self->dbg_file0BeginSeq + self->files[0].popped + self->files[1].popped)
.detail("File0Size", self->files[0].size).detail("File1Size", self->files[1].size)
.detail("File0Name", self->files[0].dbgFilename).detail("SyncedFiles", syncFiles.size());*/
committed.send(Void());
} catch (Error& e) {
delete pageMem;
CODE_PROBE(true, "push error");
CODE_PROBE(2 == syncFiles.size(), "push spanning both files error");
TraceEvent(SevError, "RDQPushAndCommitError", dbgid)
.errorUnsuppressed(e)
.detail("InitialFilename0", filename);
if (errorPromise.canBeSet())
errorPromise.sendError(e);
if (pushing.canBeSet())
pushing.sendError(e);
if (committed.canBeSet())
committed.sendError(e);
throw e;
}
return Void();
}
void updatePopped(int64_t popped) {
int64_t pop0 = std::min(popped, files[0].size - files[0].popped);
files[0].popped += pop0;
files[1].popped += popped - pop0;
}
// Set the starting point of the ring buffer, i.e., the first useful page to be read (and poped)
ACTOR static Future<Void> setPoppedPage(RawDiskQueue_TwoFiles* self, int file, int64_t page, int64_t debugSeq) {
self->files[file].popped = page * sizeof(Page);
if (file)
self->files[0].popped = self->files[0].size;
else
self->files[1].popped = 0;
self->dbg_file0BeginSeq = debugSeq - self->files[1].popped - self->files[0].popped;
// If we are starting in file 1, we truncate file 0 in case it has been corrupted.
// In particular, we are trying to avoid a dropped or corrupted write to the first page of file 0 causing it to
// be sequenced before file 1, when in fact it contains many pages that follow file 1. These ok pages may be
// incorrectly read if the machine dies after overwritting the first page of file 0 and is then recovered
if (file == 1)
wait(self->truncateFile(self, 0, 0));
return Void();
}
ACTOR static Future<Void> openFiles(RawDiskQueue_TwoFiles* self) {
state std::vector<Future<Reference<IAsyncFile>>> fs;
fs.reserve(2);
for (int i = 0; i < 2; i++)
fs.push_back(IAsyncFileSystem::filesystem()->open(self->filename(i),
IAsyncFile::OPEN_READWRITE | IAsyncFile::OPEN_UNCACHED |
IAsyncFile::OPEN_UNBUFFERED | IAsyncFile::OPEN_LOCK,
0));
wait(waitForAllReady(fs));
// Treatment of errors here is important. If only one of the two files is present
// (due to a power failure during creation or deletion, or administrative error) we don't want to
// open the queue!
if (!fs[0].isError() && !fs[1].isError()) {
// Both files were opened OK: success
} else if (fs[0].isError() && fs[0].getError().code() == error_code_file_not_found && fs[1].isError() &&
fs[1].getError().code() == error_code_file_not_found) {
// Neither file was found: we can create a new queue
// OPEN_ATOMIC_WRITE_AND_CREATE defers creation (using a .part file) until the calls to sync() below
TraceEvent("DiskQueueCreate").detail("File0", self->filename(0));
for (int i = 0; i < 2; i++)
fs[i] = IAsyncFileSystem::filesystem()->open(
self->filename(i),
IAsyncFile::OPEN_ATOMIC_WRITE_AND_CREATE | IAsyncFile::OPEN_CREATE | IAsyncFile::OPEN_READWRITE |
IAsyncFile::OPEN_UNCACHED | IAsyncFile::OPEN_UNBUFFERED | IAsyncFile::OPEN_LOCK,
0600);
// Any error here is fatal
wait(waitForAll(fs));
// sync on each file to actually create it will be done below
} else {
// One file had a more serious error or one file is present and the other is not. Die.
if (!fs[0].isError() || (fs[1].isError() && fs[1].getError().code() != error_code_file_not_found))
throw fs[1].getError();
else
throw fs[0].getError();
}
// fsync both files. This is necessary to trigger atomic file creation in the creation case above.
// It also permits the recovery code to assume that whatever it reads is durable. Otherwise a prior
// process could have written (but not synchronized) data to the file which we will read but which
// might not survive a reboot. The recovery code assumes otherwise and could corrupt the disk.
std::vector<Future<Void>> syncs;
syncs.reserve(fs.size());
for (int i = 0; i < fs.size(); i++)
syncs.push_back(fs[i].get()->sync());
wait(waitForAll(syncs));
// Successfully opened or created; fill in self->files[]
for (int i = 0; i < 2; i++)
self->files[i].setFile(fs[i].get());
return Void();
}
ACTOR static void shutdown(RawDiskQueue_TwoFiles* self, bool deleteFiles) {
// Wait for all reads and writes on the file, and all actors referencing self, to be finished
state Error error = success();
try {
wait(success(errorOr(self->lastCommit)));
// Wait for the pending operations (e.g., read) to finish before we destroy the DiskQueue, because
// tLog, instead of DiskQueue, hold the future of the pending operations.
wait(self->onSafeToDestruct());
for (int i = 0; i < 2; i++)
self->files[i].f.clear();
if (deleteFiles) {
TraceEvent("DiskQueueShutdownDeleting", self->dbgid)
.detail("File0", self->filename(0))
.detail("File1", self->filename(1));
wait(IAsyncFileSystem::filesystem()->incrementalDeleteFile(self->filename(0), false));
wait(IAsyncFileSystem::filesystem()->incrementalDeleteFile(self->filename(1), true));
}
TraceEvent("DiskQueueShutdownComplete", self->dbgid)
.detail("DeleteFiles", deleteFiles)
.detail("File0", self->filename(0));
} catch (Error& e) {
TraceEvent(SevError, "DiskQueueShutdownError", self->dbgid)
.errorUnsuppressed(e)
.detail("Reason", e.code() == error_code_platform_error ? "could not delete database" : "unknown");
error = e;
}
if (error.code() != error_code_actor_cancelled) {
if (self->stopped.canBeSet())
self->stopped.send(Void());
if (self->error.canBeSet())
self->error.send(Never());
delete self;
}
}
// Return the most recently written page, the page with largest seq number
ACTOR static UNCANCELLABLE Future<Standalone<StringRef>> readFirstAndLastPages(RawDiskQueue_TwoFiles* self,
compare_pages compare) {
state TrackMe trackMe(self);
try {
// Open both files or create both files
wait(openFiles(self));
// Get the file sizes
std::vector<Future<int64_t>> fsize;
fsize.reserve(2);
for (int i = 0; i < 2; i++)
fsize.push_back(self->files[i].f->size());
std::vector<int64_t> file_sizes = wait(getAll(fsize));
for (int i = 0; i < 2; i++) {
// SOMEDAY: If the file size is not a multiple of page size, it may never be shortened. Change this?
self->files[i].size = file_sizes[i] - file_sizes[i] % sizeof(Page);
ASSERT(self->files[i].size % sizeof(Page) == 0);
}
// Read the first pages
std::vector<Future<int>> reads;
for (int i = 0; i < 2; i++)
if (self->files[i].size > 0)
reads.push_back(self->files[i].f->read(self->firstPages[i], sizeof(Page), 0));
wait(waitForAllReadyThenThrow(reads));
// Determine which file comes first
if (compare(self->firstPages[1], self->firstPages[0])) {
std::swap(self->firstPages[0], self->firstPages[1]);
std::swap(self->files[0], self->files[1]);
}
if (!compare(self->firstPages[0], self->firstPages[0])) {
memset(self->firstPages[0], 0xFF, sizeof(Page));
}
if (!compare(self->firstPages[1], self->firstPages[1])) {
// Both files are invalid... the queue is empty!
// Begin pushing at the beginning of files[1]
// Truncate both files, since perhaps only the first pages are corrupted. This avoids cases where
// overwritting the first page and then terminating makes subsequent pages valid upon recovery.
std::vector<Future<Void>> truncates;
for (int i = 0; i < 2; ++i)
if (self->files[i].size > 0)
truncates.push_back(self->truncateFile(self, i, 0));
wait(waitForAll(truncates));
self->files[0].popped = self->files[0].size;
self->files[1].popped = 0;
memset(self->firstPages[1], 0xFF, sizeof(Page));
self->writingPos = 0;
self->readingFile = 2;
return Standalone<StringRef>();
}
// A page in files[1] is "valid" iff compare(self->firstPages[1], page)
// Binary search to find a page in files[1] that is "valid" but the next page is not valid
// Invariant: the page at begin is valid, and the page at end is invalid
state int64_t begin = 0;
state int64_t end = self->files[1].size / sizeof(Page);
state Standalone<StringRef> middlePageAllocation = makeAlignedString(sizeof(Page), sizeof(Page));
state Page* middlePage = (Page*)middlePageAllocation.begin();
while (begin + 1 != end) {
state int64_t middle = (begin + end) / 2;
ASSERT(middle > begin && middle < end); // So the loop always changes begin or end
int len = wait(self->files[1].f->read(middlePage, sizeof(Page), middle * sizeof(Page)));
ASSERT(len == sizeof(Page));
bool middleValid = compare(self->firstPages[1], middlePage);
TraceEvent("RDQBS", self->dbgid)
.detail("Begin", begin)
.detail("End", end)
.detail("Middle", middle)
.detail("Valid", middleValid)
.detail("File0Name", self->files[0].dbgFilename);
if (middleValid)
begin = middle;
else
end = middle;
}
// Now by the invariant and the loop condition, begin is a valid page and begin+1 is an invalid page
// Check that begin+1 is invalid
int len1 = wait(self->files[1].f->read(middlePage, sizeof(Page), (begin + 1) * sizeof(Page)));
ASSERT(!(len1 == sizeof(Page) && compare(self->firstPages[1], middlePage)));
// Read it
int len2 = wait(self->files[1].f->read(middlePage, sizeof(Page), begin * sizeof(Page)));
ASSERT(len2 == sizeof(Page) && compare(self->firstPages[1], middlePage));
TraceEvent("RDQEndFound", self->dbgid)
.detail("File0Name", self->files[0].dbgFilename)
.detail("Pos", begin)
.detail("FileSize", self->files[1].size);
return middlePageAllocation;
} catch (Error& e) {
bool ok = e.code() == error_code_file_not_found;
TraceEvent(ok ? SevInfo : SevError, "RDQReadFirstAndLastPagesError", self->dbgid)
.errorUnsuppressed(e)
.detail("File0Name", self->files[0].dbgFilename);
if (!self->error.isSet())
self->error.sendError(e);
throw;
}
}
// Read nPages from pageOffset*sizeof(Page) offset in file self->files[file]
ACTOR static UNCANCELLABLE Future<Standalone<StringRef>> read(RawDiskQueue_TwoFiles* self,
int file,
int pageOffset,
int nPages) {
state TrackMe trackMe(self);
state const size_t bytesRequested = nPages * sizeof(Page);
state Standalone<StringRef> result = makeAlignedString(sizeof(Page), bytesRequested);
if (file == 1)
ASSERT_WE_THINK(pageOffset * sizeof(Page) + bytesRequested <= self->writingPos);
int bytesRead =
wait(self->files[file].f->read(mutateString(result), bytesRequested, pageOffset * sizeof(Page)));
ASSERT_WE_THINK(bytesRead == bytesRequested);
return result;
}
Future<int> fillReadingBuffer() {
// If we're right at the end of a file...
if (readingPage * sizeof(Page) >= (size_t)files[readingFile].size) {
readingFile++;
readingPage = 0;
if (readingFile >= 2) {
// Recovery complete
readingBuffer.clear();
writingPos = files[1].size;
return 0;
}
}
// Read up to 1MB into readingBuffer
int len = std::min<int64_t>((files[readingFile].size / sizeof(Page) - readingPage) * sizeof(Page),
BUGGIFY_WITH_PROB(1.0) ? sizeof(Page) * deterministicRandom()->randomInt(1, 4)
: (1 << 20));
readingBuffer.clear();
readingBuffer.alignReserve(sizeof(Page), len);
void* p = readingBuffer.append(len);
auto pos = readingPage * sizeof(Page);
readingPage += len / sizeof(Page);
ASSERT(int64_t(p) % sizeof(Page) == 0);
return files[readingFile].f->read(p, len, pos);
}
ACTOR static UNCANCELLABLE Future<Standalone<StringRef>> readNextPage(RawDiskQueue_TwoFiles* self) {
state TrackMe trackMe(self);
try {
ASSERT(self->readingFile < 2);
ASSERT(self->files[0].f && self->files[1].f);
if (!self->readingBuffer.size()) {
state Future<Void> f = Void();
// if (BUGGIFY) f = delay( deterministicRandom()->random01() * 0.1 );
int read = wait(self->fillReadingBuffer());
ASSERT(read == self->readingBuffer.size());
wait(f);
}
if (!self->readingBuffer.size())
return Standalone<StringRef>();
ASSERT(self->readingBuffer.size() >= sizeof(Page));
Standalone<StringRef> result = self->readingBuffer.pop_front(sizeof(Page));
return result;
} catch (Error& e) {
CODE_PROBE(true, "Read next page error");
TraceEvent(SevError, "RDQReadNextPageError", self->dbgid)
.errorUnsuppressed(e)
.detail("File0Name", self->files[0].dbgFilename);
if (!self->error.isSet())
self->error.sendError(e);
throw;
}
}
// Set zero and free the memory from pos to the end of file self->files[file].
ACTOR static UNCANCELLABLE Future<Void> truncateFile(RawDiskQueue_TwoFiles* self, int file, int64_t pos) {
state TrackMe trackMe(self);
TraceEvent("DQTruncateFile", self->dbgid)
.detail("File", file)
.detail("Pos", pos)
.detail("File0Name", self->files[0].dbgFilename);
state Reference<IAsyncFile> f =
self->files[file].f; // Hold onto a reference in the off-chance that the DQ is removed from underneath us.
if (pos == 0) {
memset(self->firstPages[file], 0xFF, _PAGE_SIZE);
}
wait(f->zeroRange(pos, self->files[file].size - pos));
wait(self->files[file].syncQueue->onSync());
// We intentionally don't return the f->zero future, so that TrackMe is destructed after f->zero finishes.
return Void();
}
ACTOR static Future<Void> truncateBeforeLastReadPage(RawDiskQueue_TwoFiles* self) {
try {
state int file = self->readingFile;
state int64_t pos = (self->readingPage - self->readingBuffer.size() / sizeof(Page) - 1) * sizeof(Page);
state std::vector<Future<Void>> commits;
state bool swap = file == 0;
CODE_PROBE(file == 0, "truncate before last read page on file 0");
CODE_PROBE(file == 1 && pos != self->files[1].size, "truncate before last read page on file 1");
self->readingFile = 2;
self->readingBuffer.clear();
self->writingPos = pos;
while (file < 2) {
commits.push_back(self->truncateFile(self, file, pos));
file++;
pos = 0;
}
wait(waitForAll(commits));
if (swap) {
std::swap(self->files[0], self->files[1]);
std::swap(self->firstPages[0], self->firstPages[1]);
self->files[0].popped = self->files[0].size;
}
return Void();
} catch (Error& e) {
TraceEvent(SevError, "RDQTruncateBeforeLastReadPageError", self->dbgid)
.error(e)
.detail("File0Name", self->files[0].dbgFilename);
if (!self->error.isSet())
self->error.sendError(e);
throw;
}
}
};
class DiskQueue final : public IDiskQueue, public Tracked<DiskQueue> {
public:
DiskQueue(std::string basename,
std::string fileExtension,
UID dbgid,
DiskQueueVersion diskQueueVersion,
int64_t fileSizeWarningLimit)
: rawQueue(new RawDiskQueue_TwoFiles(basename, fileExtension, dbgid, fileSizeWarningLimit)), dbgid(dbgid),
diskQueueVersion(diskQueueVersion), anyPopped(false), warnAlwaysForMemory(true), nextPageSeq(0), poppedSeq(0),
lastPoppedSeq(0), lastCommittedSeq(0), pushed_page_buffer(nullptr), recovered(false), initialized(false),
nextReadLocation(-1), readBufPage(nullptr), readBufPos(0) {}
location push(StringRef contents) override {
ASSERT(recovered);
uint8_t const* begin = contents.begin();
uint8_t const* end = contents.end();
CODE_PROBE(contents.size() && pushedPageCount(), "More than one push between commits");
bool pushAtEndOfPage = contents.size() >= 4 && pushedPageCount() && backPage().remainingCapacity() < 4;
CODE_PROBE(pushAtEndOfPage, "Push right at the end of a page, possibly splitting size");
while (begin != end) {
if (!pushedPageCount() || !backPage().remainingCapacity())
addEmptyPage();
auto& p = backPage();
int s = std::min<int>(p.remainingCapacity(), end - begin);
memcpy(p.payload + p.payloadSize, begin, s);
p.payloadSize += s;
begin += s;
}
return endLocation();
}
void pop(location upTo) override {
ASSERT(!upTo.hi);
ASSERT(!recovered || upTo.lo <= endLocation());
// SS can pop pages that have not been sync.ed to disk because of concurrency:
// SS can read (i.e., pop) data at the same time or before tLog syncs the page to disk.
// This is rare in real situation but common in simulation.
// The following ASSERT is NOT part of the intended contract of IDiskQueue, but alerts the user to a known bug
// where popping
// into uncommitted pages can cause a durability failure.
// FIXME: Remove this ASSERT when popping into uncommitted pages is fixed
if (upTo.lo > lastCommittedSeq) {
TraceEvent(SevError, "DQPopUncommittedData", dbgid)
.detail("UpTo", upTo)
.detail("LastCommittedSeq", lastCommittedSeq)
.detail("File0Name", rawQueue->files[0].dbgFilename);
}
if (upTo.lo > poppedSeq) {
poppedSeq = upTo.lo;
anyPopped = true;
}
}
Future<Standalone<StringRef>> read(location from, location to, CheckHashes ch) override {
return read(this, from, to, ch);
}
int getMaxPayload() const { return Page::maxPayload; }
// Always commit an entire page. Commit overhead is the unused space in a to-be-committed page
int getCommitOverhead() const override {
if (!pushedPageCount()) {
if (!anyPopped)
return 0;
// To mark pages are poped, we push an empty page to specify that following pages were poped.
// maxPayLoad is the max. payload size, i.e., (page_size - page_header_size).
return Page::maxPayload;
} else
return backPage().remainingCapacity();
}
Future<Void> commit() override {
ASSERT(recovered);
if (!pushedPageCount()) {
if (!anyPopped)
return Void();
addEmptyPage(); // To remove poped pages, we push an empty page to specify that pages behind it were poped.
}
anyPopped = false;
backPage().popped = poppedSeq;
backPage().zeroPad();
backPage().updateHash();
// Warn users that we pushed too many pages. 8000 is an arbitrary value.
if (pushedPageCount() >= 8000) {
TraceEvent(warnAlwaysForMemory ? SevWarnAlways : SevWarn, "DiskQueueMemoryWarning", dbgid)
.suppressFor(1.0)
.detail("PushedPages", pushedPageCount())
.detail("NextPageSeq", nextPageSeq)
.detail("Details", format("%d pages", pushedPageCount()))
.detail("File0Name", rawQueue->files[0].dbgFilename);
if (g_network->isSimulated())
warnAlwaysForMemory = false;
}
/*TraceEvent("DQCommit", dbgid).detail("Pages", pushedPageCount()).detail("LastPoppedSeq", lastPoppedSeq).detail("PoppedSeq", poppedSeq).detail("NextPageSeq", nextPageSeq)
.detail("RawFile0Size", rawQueue->files[0].size).detail("RawFile1Size",
rawQueue->files[1].size).detail("WritingPos", rawQueue->writingPos) .detail("RawFile0Name",
rawQueue->files[0].dbgFilename);*/
// Since we only commit entire pages, round the last
// committed location up to the next page.
lastCommittedSeq = pageCeiling(backPage().endSeq());
auto f = rawQueue->pushAndCommit(
pushed_page_buffer->get(), pushed_page_buffer, poppedSeq / sizeof(Page) - lastPoppedSeq / sizeof(Page));
lastPoppedSeq = poppedSeq;
pushed_page_buffer = 0;
return f;
}
void stall() { rawQueue->stall(); }
Future<bool> initializeRecovery(location recoverAt) override { return initializeRecovery(this, recoverAt); }
Future<Standalone<StringRef>> readNext(int bytes) override { return readNext(this, bytes); }
// FIXME: getNextReadLocation should ASSERT( initialized ), but the memory storage engine needs
// to be changed to understand the new intiailizeRecovery protocol.
location getNextReadLocation() const override { return nextReadLocation; }
location getNextPushLocation() const override {
ASSERT(initialized);
return endLocation();
}
Future<Void> getError() const override { return rawQueue->getError(); }
Future<Void> onClosed() const override { return rawQueue->onClosed(); }
void dispose() override {
TraceEvent("DQDestroy", dbgid)
.detail("LastPoppedSeq", lastPoppedSeq)
.detail("PoppedSeq", poppedSeq)
.detail("NextPageSeq", nextPageSeq)
.detail("File0Name", rawQueue->files[0].dbgFilename);
dispose(this);
}
void close() override {
TraceEvent("DQClose", dbgid)
.detail("LastPoppedSeq", lastPoppedSeq)
.detail("PoppedSeq", poppedSeq)
.detail("NextPageSeq", nextPageSeq)
.detail("PoppedCommitted",
rawQueue->dbg_file0BeginSeq + rawQueue->files[0].popped + rawQueue->files[1].popped)
.detail("File0Name", rawQueue->files[0].dbgFilename);
close(this);
}
StorageBytes getStorageBytes() const override { return rawQueue->getStorageBytes(); }
private:
ACTOR static void dispose(DiskQueue* self) {
wait(self->onSafeToDestruct());
TraceEvent("DQDestroyDone", self->dbgid).detail("File0Name", self->rawQueue->files[0].dbgFilename);
self->rawQueue->dispose();
delete self;
}
ACTOR static void close(DiskQueue* self) {
wait(self->onSafeToDestruct());
TraceEvent("DQCloseDone", self->dbgid).detail("File0Name", self->rawQueue->files[0].dbgFilename);
self->rawQueue->close();
delete self;
}
#pragma pack(push, 1)
struct PageHeader {
union {
UID hash;
struct {
union {
uint64_t hash64;
struct {
uint32_t hash32;
uint32_t _unused;
};
};
uint16_t magic;
uint16_t implementationVersion;
};
};
uint64_t seq; // seq is the index of the virtually infinite disk queue file. Its unit is bytes.
uint64_t popped;
int32_t payloadSize;
};
// The on disk format depends on the size of PageHeader.
static_assert(sizeof(PageHeader) == 36, "PageHeader must be 36 bytes");
struct Page : PageHeader {
static const int maxPayload = _PAGE_SIZE - sizeof(PageHeader);
uint8_t payload[maxPayload];
DiskQueueVersion diskQueueVersion() const { return static_cast<DiskQueueVersion>(implementationVersion); }
int remainingCapacity() const { return maxPayload - payloadSize; }
uint64_t endSeq() const { return seq + sizeof(PageHeader) + payloadSize; }
UID checksum_hashlittle2() const {
// SOMEDAY: Better hash?
uint32_t part[2] = { 0x12345678, 0xbeefabcd };
hashlittle2(&seq, sizeof(Page) - sizeof(UID), &part[0], &part[1]);
return UID(int64_t(part[0]) << 32 | part[1], 0xFDB);
}
uint32_t checksum_crc32c() const {
return crc32c_append(0xfdbeefdb, (uint8_t*)&_unused, sizeof(Page) - sizeof(uint32_t));
}
uint64_t checksum_xxhash3() const {
return XXH3_64bits(static_cast<const void*>(&magic), sizeof(Page) - sizeof(uint64_t));
}
void updateHash() {
switch (diskQueueVersion()) {
case DiskQueueVersion::V0: {
hash = checksum_hashlittle2();
return;
}
case DiskQueueVersion::V1: {
hash32 = checksum_crc32c();
return;
}
case DiskQueueVersion::V2:
default: {
hash64 = checksum_xxhash3();
return;
}
}
}
bool checkHash() {
switch (diskQueueVersion()) {
case DiskQueueVersion::V0: {
return hash == checksum_hashlittle2();
}
case DiskQueueVersion::V1: {
return hash32 == checksum_crc32c();
}
case DiskQueueVersion::V2: {
return hash64 == checksum_xxhash3();
}
default:
return false;
}
}
void zeroPad() { memset(payload + payloadSize, 0, maxPayload - payloadSize); }
};
static_assert(sizeof(Page) == _PAGE_SIZE, "Page must be 4k");
#pragma pack(pop)
loc_t endLocation() const { return pushedPageCount() ? backPage().endSeq() : nextPageSeq; }
void addEmptyPage() {
if (pushedPageCount()) {
backPage().updateHash();
ASSERT(backPage().payloadSize == Page::maxPayload);
}
// pushed_pages.resize( pushed_pages.arena(), pushed_pages.size()+1 );
if (!pushed_page_buffer)
pushed_page_buffer = new StringBuffer(dbgid);
pushed_page_buffer->alignReserve(sizeof(Page), pushed_page_buffer->size() + sizeof(Page));
pushed_page_buffer->append(sizeof(Page));
ASSERT(nextPageSeq % sizeof(Page) == 0);
auto& p = backPage();
memset(static_cast<void*>(&p), 0, sizeof(Page)); // FIXME: unnecessary?
p.magic = 0xFDB;
switch (diskQueueVersion) {
case DiskQueueVersion::V0:
p.implementationVersion = 0;
break;
case DiskQueueVersion::V1:
p.implementationVersion = 1;
break;
case DiskQueueVersion::V2:
p.implementationVersion = 2;
break;
}
p.payloadSize = 0;
p.seq = nextPageSeq;
nextPageSeq += sizeof(Page);
p.popped = poppedSeq;
if (pushedPageCount() == 8000) {
TraceEvent("DiskQueueHighPageCount", dbgid)
.detail("PushedPages", pushedPageCount())
.detail("NextPageSeq", nextPageSeq)
.detail("File0Name", rawQueue->files[0].dbgFilename);
}
}
ACTOR static void verifyCommit(DiskQueue* self,
Future<Void> commitSynced,
StringBuffer* buffer,
loc_t start,
loc_t end) {
state TrackMe trackme(self);
try {
wait(commitSynced);
Standalone<StringRef> pagedData = wait(readPages(self, start, end));
const int startOffset = start % _PAGE_SIZE;
const int dataLen = end - start;
ASSERT(pagedData.substr(startOffset, dataLen).compare(buffer->get().substr(0, dataLen)) == 0);
} catch (Error& e) {
if (e.code() != error_code_io_error) {
delete buffer;
throw;
}
}
delete buffer;
}
// Read pages from [start, end) bytes
ACTOR static Future<Standalone<StringRef>> readPages(DiskQueue* self, location start, location end) {
state TrackMe trackme(self);
state int fromFile;
state int toFile;
state int64_t fromPage;
state int64_t toPage;
state uint64_t file0size =
self->rawQueue->files[0].size ? self->firstPages(1).seq - self->firstPages(0).seq : self->firstPages(1).seq;
ASSERT(end > start);
ASSERT(start.lo >= self->firstPages(0).seq || start.lo >= self->firstPages(1).seq);
self->findPhysicalLocation(start.lo, &fromFile, &fromPage, nullptr);
self->findPhysicalLocation(end.lo - 1, &toFile, &toPage, nullptr);
if (fromFile == 0) {
ASSERT(fromPage < file0size / _PAGE_SIZE);
}
if (toFile == 0) {
ASSERT(toPage < file0size / _PAGE_SIZE);
}
// FIXME I think there's something with nextReadLocation we can do here when initialized && !recovered.
if (fromFile == 1 && self->recovered) {
ASSERT(fromPage < self->rawQueue->writingPos / _PAGE_SIZE);
}
if (toFile == 1 && self->recovered) {
ASSERT(toPage < self->rawQueue->writingPos / _PAGE_SIZE);
}
if (fromFile == toFile) {
ASSERT(toPage >= fromPage);
Standalone<StringRef> pagedData = wait(self->rawQueue->read(fromFile, fromPage, toPage - fromPage + 1));
if (std::min(self->firstPages(0).seq, self->firstPages(1).seq) > start.lo) {
// Simulation allows for reads to be delayed and executed after overlapping subsequent
// write operations. This means that by the time our read was executed, it's possible
// that both disk queue files have been completely overwritten.
// I'm not clear what is the actual contract for read/write in this case, so simulation
// might be a bit overly aggressive here, but it's behavior we need to tolerate.
throw io_error();
}
ASSERT(((Page*)pagedData.begin())->seq == pageFloor(start.lo));
ASSERT(pagedData.size() == (toPage - fromPage + 1) * _PAGE_SIZE);
ASSERT(((Page*)pagedData.end() - 1)->seq == pageFloor(end.lo - 1));
return pagedData;
} else {
ASSERT(fromFile == 0);
state Standalone<StringRef> firstChunk;
state Standalone<StringRef> secondChunk;
wait(store(firstChunk, self->rawQueue->read(fromFile, fromPage, (file0size / sizeof(Page)) - fromPage)) &&
store(secondChunk, self->rawQueue->read(toFile, 0, toPage + 1)));
if (std::min(self->firstPages(0).seq, self->firstPages(1).seq) > start.lo) {
// See above.
throw io_error();
}
ASSERT(firstChunk.size() == ((file0size / sizeof(Page)) - fromPage) * _PAGE_SIZE);
ASSERT(((Page*)firstChunk.begin())->seq == pageFloor(start.lo));
ASSERT(secondChunk.size() == (toPage + 1) * _PAGE_SIZE);
ASSERT(((Page*)secondChunk.end() - 1)->seq == pageFloor(end.lo - 1));
return firstChunk.withSuffix(secondChunk);
}
}
ACTOR static Future<Standalone<StringRef>> read(DiskQueue* self, location start, location end, CheckHashes ch) {
// This `state` is unnecessary, but works around pagedData wrongly becoming const
// due to the actor compiler.
state Standalone<StringRef> pagedData = wait(readPages(self, start, end));
ASSERT(start.lo % sizeof(Page) == 0 || start.lo % sizeof(Page) >= sizeof(PageHeader));
int startingOffset = start.lo % sizeof(Page);
if (startingOffset > 0)
startingOffset -= sizeof(PageHeader);
ASSERT(end.lo % sizeof(Page) == 0 || end.lo % sizeof(Page) > sizeof(PageHeader));
int endingOffset = end.lo % sizeof(Page);
if (endingOffset == 0)
endingOffset = sizeof(Page);
if (endingOffset > 0)
endingOffset -= sizeof(PageHeader);
if (pageFloor(end.lo - 1) == pageFloor(start.lo)) {
// start and end are on the same page
ASSERT(pagedData.size() == sizeof(Page));
Page* data = reinterpret_cast<Page*>(const_cast<uint8_t*>(pagedData.begin()));
if (ch && !data->checkHash())
throw io_error();
if (!ch && data->payloadSize > Page::maxPayload)
throw io_error();
pagedData.contents() = pagedData.substr(sizeof(PageHeader) + startingOffset, endingOffset - startingOffset);
return pagedData;
} else {
// Reusing pagedData wastes # of pages * sizeof(PageHeader) bytes, but means
// we don't have to double allocate in a hot, memory hungry call.
uint8_t* buf = mutateString(pagedData);
Page* data = reinterpret_cast<Page*>(const_cast<uint8_t*>(pagedData.begin()));
if (ch && !data->checkHash())
throw io_error();
if (!ch && data->payloadSize > Page::maxPayload)
throw io_error();
// Only start copying from `start` in the first page.
if (data->payloadSize > startingOffset) {
const int length = data->payloadSize - startingOffset;
memmove(buf, data->payload + startingOffset, length);
buf += length;
}
data++;
if (ch && !data->checkHash())
throw io_error();
if (!ch && data->payloadSize > Page::maxPayload)
throw io_error();
// Copy all the middle pages
while (data->seq != pageFloor(end.lo - 1)) {
// These pages can have varying amounts of data, as pages with partial
// data will be zero-filled when commit is called.
const int length = data->payloadSize;
memmove(buf, data->payload, length);
buf += length;
data++;
if (ch && !data->checkHash())
throw io_error();
if (!ch && data->payloadSize > Page::maxPayload)
throw io_error();
}
// Copy only until `end` in the last page.
const int length = data->payloadSize;
memmove(buf, data->payload, std::min(endingOffset, length));
buf += std::min(endingOffset, length);
memset(buf, 0, pagedData.size() - (buf - pagedData.begin()));
Standalone<StringRef> unpagedData = pagedData.substr(0, buf - pagedData.begin());
return unpagedData;
}
}
void readFromBuffer(StringBuffer* result, int* bytes) {
// extract up to bytes from readBufPage into result
int len = std::min(readBufPage->payloadSize - readBufPos, *bytes);
if (len <= 0)
return;
result->append(StringRef(readBufPage->payload + readBufPos, len));
readBufPos += len;
*bytes -= len;
nextReadLocation += len;
}
ACTOR static Future<Standalone<StringRef>> readNext(DiskQueue* self, int bytes) {
state StringBuffer result(self->dbgid);
ASSERT(bytes >= 0);
result.clearReserve(bytes);
ASSERT(!self->recovered);
if (!self->initialized) {
bool recoveryComplete = wait(initializeRecovery(self, 0));
if (recoveryComplete) {
ASSERT(self->poppedSeq <= self->endLocation());
return Standalone<StringRef>();
}
}
loop {
if (self->readBufPage) {
self->readFromBuffer(&result, &bytes);
// if done, return
if (!bytes)
return result.str;
ASSERT(self->readBufPos == self->readBufPage->payloadSize);
self->readBufPage = 0;
self->nextReadLocation += sizeof(Page) - self->readBufPos;
self->readBufPos = 0;
}
Standalone<StringRef> page = wait(self->rawQueue->readNextPage());
if (!page.size()) {
TraceEvent("DQRecEOF", self->dbgid)
.detail("NextReadLocation", self->nextReadLocation)
.detail("File0Name", self->rawQueue->files[0].dbgFilename);
break;
}
ASSERT(page.size() == sizeof(Page));
self->readBufArena = page.arena();
self->readBufPage = (Page*)page.begin();
if (!self->readBufPage->checkHash() || self->readBufPage->seq < pageFloor(self->nextReadLocation)) {
TraceEvent("DQRecInvalidPage", self->dbgid)
.detail("NextReadLocation", self->nextReadLocation)
.detail("HashCheck", self->readBufPage->checkHash())
.detail("Seq", self->readBufPage->seq)
.detail("Expect", pageFloor(self->nextReadLocation))
.detail("File0Name", self->rawQueue->files[0].dbgFilename);
wait(self->rawQueue->truncateBeforeLastReadPage());
break;
}
//TraceEvent("DQRecPage", self->dbgid).detail("NextReadLoc", self->nextReadLocation).detail("Seq", self->readBufPage->seq).detail("Pop", self->readBufPage->popped).detail("Payload", self->readBufPage->payloadSize).detail("File0Name", self->rawQueue->files[0].dbgFilename);
ASSERT(self->readBufPage->seq == pageFloor(self->nextReadLocation));
self->lastPoppedSeq = self->readBufPage->popped;
}
// Recovery complete.
// The fully durable popped point is self->lastPoppedSeq; tell the raw queue that.
int f;
int64_t p;
bool poppedNotDurable = self->lastPoppedSeq / sizeof(Page) != self->poppedSeq / sizeof(Page);
CODE_PROBE(poppedNotDurable, "DiskQueue: Recovery popped position not fully durable");
self->findPhysicalLocation(self->lastPoppedSeq, &f, &p, "lastPoppedSeq");
wait(self->rawQueue->setPoppedPage(f, p, pageFloor(self->lastPoppedSeq)));
// Writes go at the end of our reads (but on the next page)
self->nextPageSeq = pageFloor(self->nextReadLocation);
if (self->nextReadLocation % sizeof(Page) > sizeof(PageHeader))
self->nextPageSeq += sizeof(Page);
TraceEvent("DQRecovered", self->dbgid)
.detail("LastPoppedSeq", self->lastPoppedSeq)
.detail("PoppedSeq", self->poppedSeq)
.detail("NextPageSeq", self->nextPageSeq)
.detail("File0Name", self->rawQueue->files[0].dbgFilename);
self->recovered = true;
ASSERT(self->poppedSeq <= self->endLocation());
CODE_PROBE(result.size() == 0, "End of queue at border between reads");
CODE_PROBE(result.size() != 0, "Partial read at end of queue");
// The next read location isn't necessarily the end of the last commit, but this is sufficient for helping us
// check an ASSERTion
self->lastCommittedSeq = self->nextReadLocation;
return result.str;
}
// recoverAt is the minimum position in the disk queue file that needs to be read to restore log's states.
// This allows log to read only a small portion of the most recent data from a large (e.g., 10GB) disk file.
// This is particularly useful for logSpilling feature.
ACTOR static Future<bool> initializeRecovery(DiskQueue* self, location recoverAt) {
if (self->initialized) {
return self->recovered;
}
Standalone<StringRef> lastPageData = wait(self->rawQueue->readFirstAndLastPages(&comparePages));
self->initialized = true;
if (!lastPageData.size()) {
// There are no valid pages, so apparently this is a completely empty queue
self->nextReadLocation = 0;
self->lastCommittedSeq = 0;
self->recovered = true;
return true;
}
Page* lastPage = (Page*)lastPageData.begin();
self->poppedSeq = lastPage->popped;
self->nextReadLocation = std::max(recoverAt.lo, self->poppedSeq);
/*
state std::auto_ptr<Page> testPage(new Page);
state int fileNum;
for( fileNum=0; fileNum<2; fileNum++) {
state int sizeNum;
for( sizeNum=0; sizeNum < self->rawQueue->files[fileNum].size; sizeNum += sizeof(Page) ) {
wait(success( self->rawQueue->files[fileNum].f->read( testPage.get(), sizeof(Page), sizeNum ) ));
TraceEvent("PageData").detail("File", self->rawQueue->files[fileNum].dbgFilename).detail("SizeNum", sizeNum).detail("Seq", testPage->seq).detail("Hash", testPage->checkHash()).detail("Popped", testPage->popped);
}
}
*/
int file;
int64_t page;
self->findPhysicalLocation(self->nextReadLocation, &file, &page, "FirstReadLocation");
self->rawQueue->setStartPage(file, page);
self->readBufPos = self->nextReadLocation % sizeof(Page) - sizeof(PageHeader);
if (self->readBufPos < 0) {
self->nextReadLocation -= self->readBufPos;
self->readBufPos = 0;
}
TraceEvent("DQRecStart", self->dbgid)
.detail("ReadBufPos", self->readBufPos)
.detail("NextReadLoc", self->nextReadLocation)
.detail("Popped", self->poppedSeq)
.detail("MinRecoverAt", recoverAt)
.detail("File0Name", self->rawQueue->files[0].dbgFilename);
return false;
}
Page& firstPages(int i) {
ASSERT(initialized);
return *(Page*)rawQueue->firstPages[i];
}
void findPhysicalLocation(loc_t loc, int* file, int64_t* page, const char* context) {
bool ok = false;
if (context)
TraceEvent(SevInfo, "FindPhysicalLocation", dbgid)
.detail("Page0Valid", firstPages(0).checkHash())
.detail("Page0Seq", firstPages(0).seq)
.detail("Page1Valid", firstPages(1).checkHash())
.detail("Page1Seq", firstPages(1).seq)
.detail("Location", loc)
.detail("Context", context)
.detail("File0Name", rawQueue->files[0].dbgFilename);
for (int i = 1; i >= 0; i--) {
ASSERT_WE_THINK(firstPages(i).checkHash());
if (firstPages(i).seq <= (size_t)loc) {
*file = i;
*page = (loc - firstPages(i).seq) / sizeof(Page);
if (context)
TraceEvent("FoundPhysicalLocation", dbgid)
.detail("PageIndex", i)
.detail("PageLocation", *page)
.detail("SizeofPage", sizeof(Page))
.detail("PageSequence", firstPages(i).seq)
.detail("Location", loc)
.detail("Context", context)
.detail("File0Name", rawQueue->files[0].dbgFilename);
ok = true;
break;
}
}
if (!ok)
TraceEvent(SevError, "DiskQueueLocationError", dbgid)
.detail("Page0Valid", firstPages(0).checkHash())
.detail("Page0Seq", firstPages(0).seq)
.detail("Page1Valid", firstPages(1).checkHash())
.detail("Page1Seq", firstPages(1).seq)
.detail("Location", loc)
.detail("Context", context ? context : "")
.detail("File0Name", rawQueue->files[0].dbgFilename);
ASSERT(ok);
}
// isValid(firstPage) == compare(firstPage, firstPage)
// isValid(otherPage) == compare(firstPage, otherPage)
// Swap file1, file2 if comparePages( file2.firstPage, file1.firstPage )
static bool comparePages(void* v1, void* v2) {
Page* p1 = (Page*)v1;
Page* p2 = (Page*)v2;
return p2->checkHash() && (p2->seq >= p1->seq || !p1->checkHash());
}
RawDiskQueue_TwoFiles* rawQueue;
UID dbgid;
DiskQueueVersion diskQueueVersion;
bool anyPopped; // pop() has been called since the most recent call to commit()
bool warnAlwaysForMemory;
loc_t nextPageSeq, poppedSeq;
loc_t lastPoppedSeq; // poppedSeq the last time commit was called.
loc_t lastCommittedSeq; // The seq location where the last commit finishes at.
// Buffer of pushed pages that haven't been committed. The last one (backPage()) is still mutable.
StringBuffer* pushed_page_buffer;
Page& backPage() {
ASSERT(pushedPageCount());
return ((Page*)pushed_page_buffer->get().end())[-1];
}
Page const& backPage() const { return ((Page*)pushed_page_buffer->get().end())[-1]; }
int pushedPageCount() const { return pushed_page_buffer ? pushed_page_buffer->size() / sizeof(Page) : 0; }
// Recovery state
bool recovered;
bool initialized;
loc_t nextReadLocation;
Arena readBufArena;
Page* readBufPage;
int readBufPos;
};
// A class wrapping DiskQueue which prevents uncommitted data from being popped.
//
// Once upon a time, it was intended to allow popping uncommitted data
// by performing two commits when uncommitted data is popped:
// Commit 1 - pop only previously committed data and push new data (i.e., commit uncommitted data)
// Commit 2 - finish pop into uncommitted data
//
// Now, instead, we only use this to catch errors in tlog logic where
// we attempt to pop too much.
class DiskQueue_PopUncommitted final : public IDiskQueue {
public:
DiskQueue_PopUncommitted(std::string basename,
std::string fileExtension,
UID dbgid,
DiskQueueVersion diskQueueVersion,
int64_t fileSizeWarningLimit)
: queue(new DiskQueue(basename, fileExtension, dbgid, diskQueueVersion, fileSizeWarningLimit)), pushed(0),
popped(0), committed(0){};
// IClosable
Future<Void> getError() const override { return queue->getError(); }
Future<Void> onClosed() const override { return queue->onClosed(); }
void dispose() override {
queue->dispose();
delete this;
}
void close() override {
queue->close();
delete this;
}
// IDiskQueue
Future<bool> initializeRecovery(location recoverAt) override { return queue->initializeRecovery(recoverAt); }
Future<Standalone<StringRef>> readNext(int bytes) override { return readNext(this, bytes); }
location getNextReadLocation() const override { return queue->getNextReadLocation(); }
Future<Standalone<StringRef>> read(location start, location end, CheckHashes ch) override {
return queue->read(start, end, ch);
}
location getNextPushLocation() const override { return queue->getNextPushLocation(); }
location push(StringRef contents) override {
pushed = queue->push(contents);
return pushed;
}
void pop(location upTo) override {
popped = std::max(popped, upTo);
ASSERT_WE_THINK(committed >= popped);
queue->pop(std::min(committed, popped));
}
int getCommitOverhead() const override {
return queue->getCommitOverhead() + (popped > committed ? queue->getMaxPayload() : 0);
}
Future<Void> commit() override {
location pushLocation = pushed;
location popLocation = popped;
Future<Void> commitFuture = queue->commit();
bool updatePop = popLocation > committed;
// Since we only commit entire pages, round the last
// committed location up to the next page.
committed = location(pushLocation.hi, pageCeiling(pushLocation.lo));
if (updatePop) {
ASSERT_WE_THINK(false);
ASSERT(popLocation <= committed);
queue->stall(); // Don't permit this pipelined commit to write anything to disk until the previous commit is
// totally finished
pop(popLocation);
commitFuture = commitFuture && queue->commit();
} else {
CODE_PROBE(true, "No uncommitted data was popped");
}
return commitFuture;
}
StorageBytes getStorageBytes() const override { return queue->getStorageBytes(); }
private:
DiskQueue* queue;
location pushed;
location popped;
location committed;
ACTOR static Future<Standalone<StringRef>> readNext(DiskQueue_PopUncommitted* self, int bytes) {
Standalone<StringRef> str = wait(self->queue->readNext(bytes));
if (str.size() < bytes)
self->pushed = self->getNextReadLocation();
return str;
}
};
IDiskQueue* openDiskQueue(std::string basename,
std::string ext,
UID dbgid,
DiskQueueVersion dqv,
int64_t fileSizeWarningLimit) {
return new DiskQueue_PopUncommitted(basename, ext, dbgid, dqv, fileSizeWarningLimit);
}
TEST_CASE("performance/fdbserver/DiskQueue") {
state IDiskQueue* queue =
openDiskQueue("test-", "fdq", deterministicRandom()->randomUniqueID(), DiskQueueVersion::V2);
state std::string valueString = std::string(10e6, '.');
state StringRef valueStr((uint8_t*)valueString.c_str(), 10e6);
state std::deque<IDiskQueue::location> locations;
state int loopCount = 0;
state Future<Void> lastCommit = Void();
bool fullyRecovered = wait(queue->initializeRecovery(0));
if (!fullyRecovered) {
loop {
Standalone<StringRef> h = wait(queue->readNext(1e6));
if (h.size() < 1e6) {
break;
}
}
}
while (loopCount < 4000) {
if (loopCount % 100 == 0) {
printf("loop count: %d\n", loopCount);
}
if (++loopCount % 2 == 0) {
state IDiskQueue::location frontLocation = locations.front();
locations.pop_front();
if (locations.size() > 10) {
Standalone<StringRef> r = wait(queue->read(frontLocation, locations.front(), CheckHashes::True));
}
queue->pop(frontLocation);
}
wait(delay(0.001));
locations.push_back(queue->push(valueStr));
Future<Void> prevCommit = lastCommit;
lastCommit = queue->commit();
wait(prevCommit);
}
queue->dispose();
wait(queue->onClosed());
return Void();
}
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