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snappy/snappy_unittest.cc
Chris Mumford c76b053449 Sync TODO and comment processing with external repo. 
Copybara transforms code slightly different than MOE. One
example is the TODO username stripping where Copybara
produces different results than MOE did. This change
moves the Copybara versions of comments to the public
repository.

Note: These changes didn't originate in cl/247950252.

PiperOrigin-RevId: 247950252
2019-05-14 11:02:57 -07:00

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// Copyright 2005 and onwards Google Inc.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include <math.h>
#include <stdlib.h>
#include <algorithm>
#include <random>
#include <string>
#include <utility>
#include <vector>
#include "snappy.h"
#include "snappy-internal.h"
#include "snappy-test.h"
#include "snappy-sinksource.h"
DEFINE_int32(start_len, -1,
"Starting prefix size for testing (-1: just full file contents)");
DEFINE_int32(end_len, -1,
"Starting prefix size for testing (-1: just full file contents)");
DEFINE_int32(bytes, 10485760,
"How many bytes to compress/uncompress per file for timing");
DEFINE_bool(zlib, false,
"Run zlib compression (http://www.zlib.net)");
DEFINE_bool(lzo, false,
"Run LZO compression (http://www.oberhumer.com/opensource/lzo/)");
DEFINE_bool(snappy, true, "Run snappy compression");
DEFINE_bool(write_compressed, false,
"Write compressed versions of each file to <file>.comp");
DEFINE_bool(write_uncompressed, false,
"Write uncompressed versions of each file to <file>.uncomp");
DEFINE_bool(snappy_dump_decompression_table, false,
"If true, we print the decompression table during tests.");
namespace snappy {
#if defined(HAVE_FUNC_MMAP) && defined(HAVE_FUNC_SYSCONF)
// To test against code that reads beyond its input, this class copies a
// string to a newly allocated group of pages, the last of which
// is made unreadable via mprotect. Note that we need to allocate the
// memory with mmap(), as POSIX allows mprotect() only on memory allocated
// with mmap(), and some malloc/posix_memalign implementations expect to
// be able to read previously allocated memory while doing heap allocations.
class DataEndingAtUnreadablePage {
public:
explicit DataEndingAtUnreadablePage(const string& s) {
const size_t page_size = sysconf(_SC_PAGESIZE);
const size_t size = s.size();
// Round up space for string to a multiple of page_size.
size_t space_for_string = (size + page_size - 1) & ~(page_size - 1);
alloc_size_ = space_for_string + page_size;
mem_ = mmap(NULL, alloc_size_,
PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
CHECK_NE(MAP_FAILED, mem_);
protected_page_ = reinterpret_cast<char*>(mem_) + space_for_string;
char* dst = protected_page_ - size;
memcpy(dst, s.data(), size);
data_ = dst;
size_ = size;
// Make guard page unreadable.
CHECK_EQ(0, mprotect(protected_page_, page_size, PROT_NONE));
}
~DataEndingAtUnreadablePage() {
const size_t page_size = sysconf(_SC_PAGESIZE);
// Undo the mprotect.
CHECK_EQ(0, mprotect(protected_page_, page_size, PROT_READ|PROT_WRITE));
CHECK_EQ(0, munmap(mem_, alloc_size_));
}
const char* data() const { return data_; }
size_t size() const { return size_; }
private:
size_t alloc_size_;
void* mem_;
char* protected_page_;
const char* data_;
size_t size_;
};
#else // defined(HAVE_FUNC_MMAP) && defined(HAVE_FUNC_SYSCONF)
// Fallback for systems without mmap.
typedef string DataEndingAtUnreadablePage;
#endif
enum CompressorType {
ZLIB, LZO, SNAPPY
};
const char* names[] = {
"ZLIB", "LZO", "SNAPPY"
};
static size_t MinimumRequiredOutputSpace(size_t input_size,
CompressorType comp) {
switch (comp) {
#ifdef ZLIB_VERSION
case ZLIB:
return ZLib::MinCompressbufSize(input_size);
#endif // ZLIB_VERSION
#ifdef LZO_VERSION
case LZO:
return input_size + input_size/64 + 16 + 3;
#endif // LZO_VERSION
case SNAPPY:
return snappy::MaxCompressedLength(input_size);
default:
LOG(FATAL) << "Unknown compression type number " << comp;
return 0;
}
}
// Returns true if we successfully compressed, false otherwise.
//
// If compressed_is_preallocated is set, do not resize the compressed buffer.
// This is typically what you want for a benchmark, in order to not spend
// time in the memory allocator. If you do set this flag, however,
// "compressed" must be preinitialized to at least MinCompressbufSize(comp)
// number of bytes, and may contain junk bytes at the end after return.
static bool Compress(const char* input, size_t input_size, CompressorType comp,
string* compressed, bool compressed_is_preallocated) {
if (!compressed_is_preallocated) {
compressed->resize(MinimumRequiredOutputSpace(input_size, comp));
}
switch (comp) {
#ifdef ZLIB_VERSION
case ZLIB: {
ZLib zlib;
uLongf destlen = compressed->size();
int ret = zlib.Compress(
reinterpret_cast<Bytef*>(string_as_array(compressed)),
&destlen,
reinterpret_cast<const Bytef*>(input),
input_size);
CHECK_EQ(Z_OK, ret);
if (!compressed_is_preallocated) {
compressed->resize(destlen);
}
return true;
}
#endif // ZLIB_VERSION
#ifdef LZO_VERSION
case LZO: {
unsigned char* mem = new unsigned char[LZO1X_1_15_MEM_COMPRESS];
lzo_uint destlen;
int ret = lzo1x_1_15_compress(
reinterpret_cast<const uint8*>(input),
input_size,
reinterpret_cast<uint8*>(string_as_array(compressed)),
&destlen,
mem);
CHECK_EQ(LZO_E_OK, ret);
delete[] mem;
if (!compressed_is_preallocated) {
compressed->resize(destlen);
}
break;
}
#endif // LZO_VERSION
case SNAPPY: {
size_t destlen;
snappy::RawCompress(input, input_size,
string_as_array(compressed),
&destlen);
CHECK_LE(destlen, snappy::MaxCompressedLength(input_size));
if (!compressed_is_preallocated) {
compressed->resize(destlen);
}
break;
}
default: {
return false; // the asked-for library wasn't compiled in
}
}
return true;
}
static bool Uncompress(const string& compressed, CompressorType comp,
int size, string* output) {
switch (comp) {
#ifdef ZLIB_VERSION
case ZLIB: {
output->resize(size);
ZLib zlib;
uLongf destlen = output->size();
int ret = zlib.Uncompress(
reinterpret_cast<Bytef*>(string_as_array(output)),
&destlen,
reinterpret_cast<const Bytef*>(compressed.data()),
compressed.size());
CHECK_EQ(Z_OK, ret);
CHECK_EQ(static_cast<uLongf>(size), destlen);
break;
}
#endif // ZLIB_VERSION
#ifdef LZO_VERSION
case LZO: {
output->resize(size);
lzo_uint destlen;
int ret = lzo1x_decompress(
reinterpret_cast<const uint8*>(compressed.data()),
compressed.size(),
reinterpret_cast<uint8*>(string_as_array(output)),
&destlen,
NULL);
CHECK_EQ(LZO_E_OK, ret);
CHECK_EQ(static_cast<lzo_uint>(size), destlen);
break;
}
#endif // LZO_VERSION
case SNAPPY: {
snappy::RawUncompress(compressed.data(), compressed.size(),
string_as_array(output));
break;
}
default: {
return false; // the asked-for library wasn't compiled in
}
}
return true;
}
static void Measure(const char* data,
size_t length,
CompressorType comp,
int repeats,
int block_size) {
// Run tests a few time and pick median running times
static const int kRuns = 5;
double ctime[kRuns];
double utime[kRuns];
int compressed_size = 0;
{
// Chop the input into blocks
int num_blocks = (length + block_size - 1) / block_size;
std::vector<const char*> input(num_blocks);
std::vector<size_t> input_length(num_blocks);
std::vector<string> compressed(num_blocks);
std::vector<string> output(num_blocks);
for (int b = 0; b < num_blocks; b++) {
int input_start = b * block_size;
int input_limit = std::min<int>((b+1)*block_size, length);
input[b] = data+input_start;
input_length[b] = input_limit-input_start;
// Pre-grow the output buffer so we don't measure string append time.
compressed[b].resize(MinimumRequiredOutputSpace(block_size, comp));
}
// First, try one trial compression to make sure the code is compiled in
if (!Compress(input[0], input_length[0], comp, &compressed[0], true)) {
LOG(WARNING) << "Skipping " << names[comp] << ": "
<< "library not compiled in";
return;
}
for (int run = 0; run < kRuns; run++) {
CycleTimer ctimer, utimer;
for (int b = 0; b < num_blocks; b++) {
// Pre-grow the output buffer so we don't measure string append time.
compressed[b].resize(MinimumRequiredOutputSpace(block_size, comp));
}
ctimer.Start();
for (int b = 0; b < num_blocks; b++)
for (int i = 0; i < repeats; i++)
Compress(input[b], input_length[b], comp, &compressed[b], true);
ctimer.Stop();
// Compress once more, with resizing, so we don't leave junk
// at the end that will confuse the decompressor.
for (int b = 0; b < num_blocks; b++) {
Compress(input[b], input_length[b], comp, &compressed[b], false);
}
for (int b = 0; b < num_blocks; b++) {
output[b].resize(input_length[b]);
}
utimer.Start();
for (int i = 0; i < repeats; i++)
for (int b = 0; b < num_blocks; b++)
Uncompress(compressed[b], comp, input_length[b], &output[b]);
utimer.Stop();
ctime[run] = ctimer.Get();
utime[run] = utimer.Get();
}
compressed_size = 0;
for (size_t i = 0; i < compressed.size(); i++) {
compressed_size += compressed[i].size();
}
}
std::sort(ctime, ctime + kRuns);
std::sort(utime, utime + kRuns);
const int med = kRuns/2;
float comp_rate = (length / ctime[med]) * repeats / 1048576.0;
float uncomp_rate = (length / utime[med]) * repeats / 1048576.0;
string x = names[comp];
x += ":";
string urate = (uncomp_rate >= 0)
? StringPrintf("%.1f", uncomp_rate)
: string("?");
printf("%-7s [b %dM] bytes %6d -> %6d %4.1f%% "
"comp %5.1f MB/s uncomp %5s MB/s\n",
x.c_str(),
block_size/(1<<20),
static_cast<int>(length), static_cast<uint32>(compressed_size),
(compressed_size * 100.0) / std::max<int>(1, length),
comp_rate,
urate.c_str());
}
static int VerifyString(const string& input) {
string compressed;
DataEndingAtUnreadablePage i(input);
const size_t written = snappy::Compress(i.data(), i.size(), &compressed);
CHECK_EQ(written, compressed.size());
CHECK_LE(compressed.size(),
snappy::MaxCompressedLength(input.size()));
CHECK(snappy::IsValidCompressedBuffer(compressed.data(), compressed.size()));
string uncompressed;
DataEndingAtUnreadablePage c(compressed);
CHECK(snappy::Uncompress(c.data(), c.size(), &uncompressed));
CHECK_EQ(uncompressed, input);
return uncompressed.size();
}
static void VerifyStringSink(const string& input) {
string compressed;
DataEndingAtUnreadablePage i(input);
const size_t written = snappy::Compress(i.data(), i.size(), &compressed);
CHECK_EQ(written, compressed.size());
CHECK_LE(compressed.size(),
snappy::MaxCompressedLength(input.size()));
CHECK(snappy::IsValidCompressedBuffer(compressed.data(), compressed.size()));
string uncompressed;
uncompressed.resize(input.size());
snappy::UncheckedByteArraySink sink(string_as_array(&uncompressed));
DataEndingAtUnreadablePage c(compressed);
snappy::ByteArraySource source(c.data(), c.size());
CHECK(snappy::Uncompress(&source, &sink));
CHECK_EQ(uncompressed, input);
}
static void VerifyIOVec(const string& input) {
string compressed;
DataEndingAtUnreadablePage i(input);
const size_t written = snappy::Compress(i.data(), i.size(), &compressed);
CHECK_EQ(written, compressed.size());
CHECK_LE(compressed.size(),
snappy::MaxCompressedLength(input.size()));
CHECK(snappy::IsValidCompressedBuffer(compressed.data(), compressed.size()));
// Try uncompressing into an iovec containing a random number of entries
// ranging from 1 to 10.
char* buf = new char[input.size()];
std::minstd_rand0 rng(input.size());
std::uniform_int_distribution<size_t> uniform_1_to_10(1, 10);
size_t num = uniform_1_to_10(rng);
if (input.size() < num) {
num = input.size();
}
struct iovec* iov = new iovec[num];
int used_so_far = 0;
std::bernoulli_distribution one_in_five(1.0 / 5);
for (size_t i = 0; i < num; ++i) {
assert(used_so_far < input.size());
iov[i].iov_base = buf + used_so_far;
if (i == num - 1) {
iov[i].iov_len = input.size() - used_so_far;
} else {
// Randomly choose to insert a 0 byte entry.
if (one_in_five(rng)) {
iov[i].iov_len = 0;
} else {
std::uniform_int_distribution<size_t> uniform_not_used_so_far(
0, input.size() - used_so_far - 1);
iov[i].iov_len = uniform_not_used_so_far(rng);
}
}
used_so_far += iov[i].iov_len;
}
CHECK(snappy::RawUncompressToIOVec(
compressed.data(), compressed.size(), iov, num));
CHECK(!memcmp(buf, input.data(), input.size()));
delete[] iov;
delete[] buf;
}
// Test that data compressed by a compressor that does not
// obey block sizes is uncompressed properly.
static void VerifyNonBlockedCompression(const string& input) {
if (input.length() > snappy::kBlockSize) {
// We cannot test larger blocks than the maximum block size, obviously.
return;
}
string prefix;
Varint::Append32(&prefix, input.size());
// Setup compression table
snappy::internal::WorkingMemory wmem(input.size());
int table_size;
uint16* table = wmem.GetHashTable(input.size(), &table_size);
// Compress entire input in one shot
string compressed;
compressed += prefix;
compressed.resize(prefix.size()+snappy::MaxCompressedLength(input.size()));
char* dest = string_as_array(&compressed) + prefix.size();
char* end = snappy::internal::CompressFragment(input.data(), input.size(),
dest, table, table_size);
compressed.resize(end - compressed.data());
// Uncompress into string
string uncomp_str;
CHECK(snappy::Uncompress(compressed.data(), compressed.size(), &uncomp_str));
CHECK_EQ(uncomp_str, input);
// Uncompress using source/sink
string uncomp_str2;
uncomp_str2.resize(input.size());
snappy::UncheckedByteArraySink sink(string_as_array(&uncomp_str2));
snappy::ByteArraySource source(compressed.data(), compressed.size());
CHECK(snappy::Uncompress(&source, &sink));
CHECK_EQ(uncomp_str2, input);
// Uncompress into iovec
{
static const int kNumBlocks = 10;
struct iovec vec[kNumBlocks];
const int block_size = 1 + input.size() / kNumBlocks;
string iovec_data(block_size * kNumBlocks, 'x');
for (int i = 0; i < kNumBlocks; i++) {
vec[i].iov_base = string_as_array(&iovec_data) + i * block_size;
vec[i].iov_len = block_size;
}
CHECK(snappy::RawUncompressToIOVec(compressed.data(), compressed.size(),
vec, kNumBlocks));
CHECK_EQ(string(iovec_data.data(), input.size()), input);
}
}
// Expand the input so that it is at least K times as big as block size
static string Expand(const string& input) {
static const int K = 3;
string data = input;
while (data.size() < K * snappy::kBlockSize) {
data += input;
}
return data;
}
static int Verify(const string& input) {
VLOG(1) << "Verifying input of size " << input.size();
// Compress using string based routines
const int result = VerifyString(input);
// Verify using sink based routines
VerifyStringSink(input);
VerifyNonBlockedCompression(input);
VerifyIOVec(input);
if (!input.empty()) {
const string expanded = Expand(input);
VerifyNonBlockedCompression(expanded);
VerifyIOVec(input);
}
return result;
}
static bool IsValidCompressedBuffer(const string& c) {
return snappy::IsValidCompressedBuffer(c.data(), c.size());
}
static bool Uncompress(const string& c, string* u) {
return snappy::Uncompress(c.data(), c.size(), u);
}
// This test checks to ensure that snappy doesn't coredump if it gets
// corrupted data.
TEST(CorruptedTest, VerifyCorrupted) {
string source = "making sure we don't crash with corrupted input";
VLOG(1) << source;
string dest;
string uncmp;
snappy::Compress(source.data(), source.size(), &dest);
// Mess around with the data. It's hard to simulate all possible
// corruptions; this is just one example ...
CHECK_GT(dest.size(), 3);
dest[1]--;
dest[3]++;
// this really ought to fail.
CHECK(!IsValidCompressedBuffer(dest));
CHECK(!Uncompress(dest, &uncmp));
// This is testing for a security bug - a buffer that decompresses to 100k
// but we lie in the snappy header and only reserve 0 bytes of memory :)
source.resize(100000);
for (size_t i = 0; i < source.length(); ++i) {
source[i] = 'A';
}
snappy::Compress(source.data(), source.size(), &dest);
dest[0] = dest[1] = dest[2] = dest[3] = 0;
CHECK(!IsValidCompressedBuffer(dest));
CHECK(!Uncompress(dest, &uncmp));
if (sizeof(void *) == 4) {
// Another security check; check a crazy big length can't DoS us with an
// over-allocation.
// Currently this is done only for 32-bit builds. On 64-bit builds,
// where 3 GB might be an acceptable allocation size, Uncompress()
// attempts to decompress, and sometimes causes the test to run out of
// memory.
dest[0] = dest[1] = dest[2] = dest[3] = '\xff';
// This decodes to a really large size, i.e., about 3 GB.
dest[4] = 'k';
CHECK(!IsValidCompressedBuffer(dest));
CHECK(!Uncompress(dest, &uncmp));
} else {
LOG(WARNING) << "Crazy decompression lengths not checked on 64-bit build";
}
// This decodes to about 2 MB; much smaller, but should still fail.
dest[0] = dest[1] = dest[2] = '\xff';
dest[3] = 0x00;
CHECK(!IsValidCompressedBuffer(dest));
CHECK(!Uncompress(dest, &uncmp));
// try reading stuff in from a bad file.
for (int i = 1; i <= 3; ++i) {
string data = ReadTestDataFile(StringPrintf("baddata%d.snappy", i).c_str(),
0);
string uncmp;
// check that we don't return a crazy length
size_t ulen;
CHECK(!snappy::GetUncompressedLength(data.data(), data.size(), &ulen)
|| (ulen < (1<<20)));
uint32 ulen2;
snappy::ByteArraySource source(data.data(), data.size());
CHECK(!snappy::GetUncompressedLength(&source, &ulen2) ||
(ulen2 < (1<<20)));
CHECK(!IsValidCompressedBuffer(data));
CHECK(!Uncompress(data, &uncmp));
}
}
// Helper routines to construct arbitrary compressed strings.
// These mirror the compression code in snappy.cc, but are copied
// here so that we can bypass some limitations in the how snappy.cc
// invokes these routines.
static void AppendLiteral(string* dst, const string& literal) {
if (literal.empty()) return;
int n = literal.size() - 1;
if (n < 60) {
// Fit length in tag byte
dst->push_back(0 | (n << 2));
} else {
// Encode in upcoming bytes
char number[4];
int count = 0;
while (n > 0) {
number[count++] = n & 0xff;
n >>= 8;
}
dst->push_back(0 | ((59+count) << 2));
*dst += string(number, count);
}
*dst += literal;
}
static void AppendCopy(string* dst, int offset, int length) {
while (length > 0) {
// Figure out how much to copy in one shot
int to_copy;
if (length >= 68) {
to_copy = 64;
} else if (length > 64) {
to_copy = 60;
} else {
to_copy = length;
}
length -= to_copy;
if ((to_copy >= 4) && (to_copy < 12) && (offset < 2048)) {
assert(to_copy-4 < 8); // Must fit in 3 bits
dst->push_back(1 | ((to_copy-4) << 2) | ((offset >> 8) << 5));
dst->push_back(offset & 0xff);
} else if (offset < 65536) {
dst->push_back(2 | ((to_copy-1) << 2));
dst->push_back(offset & 0xff);
dst->push_back(offset >> 8);
} else {
dst->push_back(3 | ((to_copy-1) << 2));
dst->push_back(offset & 0xff);
dst->push_back((offset >> 8) & 0xff);
dst->push_back((offset >> 16) & 0xff);
dst->push_back((offset >> 24) & 0xff);
}
}
}
TEST(Snappy, SimpleTests) {
Verify("");
Verify("a");
Verify("ab");
Verify("abc");
Verify("aaaaaaa" + string(16, 'b') + string("aaaaa") + "abc");
Verify("aaaaaaa" + string(256, 'b') + string("aaaaa") + "abc");
Verify("aaaaaaa" + string(2047, 'b') + string("aaaaa") + "abc");
Verify("aaaaaaa" + string(65536, 'b') + string("aaaaa") + "abc");
Verify("abcaaaaaaa" + string(65536, 'b') + string("aaaaa") + "abc");
}
// Verify max blowup (lots of four-byte copies)
TEST(Snappy, MaxBlowup) {
std::mt19937 rng;
std::uniform_int_distribution<int> uniform_byte(0, 255);
string input;
for (int i = 0; i < 80000; ++i)
input.push_back(static_cast<char>(uniform_byte(rng)));
for (int i = 0; i < 80000; i += 4) {
string four_bytes(input.end() - i - 4, input.end() - i);
input.append(four_bytes);
}
Verify(input);
}
TEST(Snappy, RandomData) {
std::minstd_rand0 rng(FLAGS_test_random_seed);
std::uniform_int_distribution<int> uniform_0_to_3(0, 3);
std::uniform_int_distribution<int> uniform_0_to_8(0, 8);
std::uniform_int_distribution<int> uniform_byte(0, 255);
std::uniform_int_distribution<size_t> uniform_4k(0, 4095);
std::uniform_int_distribution<size_t> uniform_64k(0, 65535);
std::bernoulli_distribution one_in_ten(1.0 / 10);
constexpr int num_ops = 20000;
for (int i = 0; i < num_ops; i++) {
if ((i % 1000) == 0) {
VLOG(0) << "Random op " << i << " of " << num_ops;
}
string x;
size_t len = uniform_4k(rng);
if (i < 100) {
len = 65536 + uniform_64k(rng);
}
while (x.size() < len) {
int run_len = 1;
if (one_in_ten(rng)) {
int skewed_bits = uniform_0_to_8(rng);
// int is guaranteed to hold at least 16 bits, this uses at most 8 bits.
std::uniform_int_distribution<int> skewed_low(0,
(1 << skewed_bits) - 1);
run_len = skewed_low(rng);
}
char c = static_cast<char>(uniform_byte(rng));
if (i >= 100) {
int skewed_bits = uniform_0_to_3(rng);
// int is guaranteed to hold at least 16 bits, this uses at most 3 bits.
std::uniform_int_distribution<int> skewed_low(0,
(1 << skewed_bits) - 1);
c = static_cast<char>(skewed_low(rng));
}
while (run_len-- > 0 && x.size() < len) {
x.push_back(c);
}
}
Verify(x);
}
}
TEST(Snappy, FourByteOffset) {
// The new compressor cannot generate four-byte offsets since
// it chops up the input into 32KB pieces. So we hand-emit the
// copy manually.
// The two fragments that make up the input string.
string fragment1 = "012345689abcdefghijklmnopqrstuvwxyz";
string fragment2 = "some other string";
// How many times each fragment is emitted.
const int n1 = 2;
const int n2 = 100000 / fragment2.size();
const int length = n1 * fragment1.size() + n2 * fragment2.size();
string compressed;
Varint::Append32(&compressed, length);
AppendLiteral(&compressed, fragment1);
string src = fragment1;
for (int i = 0; i < n2; i++) {
AppendLiteral(&compressed, fragment2);
src += fragment2;
}
AppendCopy(&compressed, src.size(), fragment1.size());
src += fragment1;
CHECK_EQ(length, src.size());
string uncompressed;
CHECK(snappy::IsValidCompressedBuffer(compressed.data(), compressed.size()));
CHECK(snappy::Uncompress(compressed.data(), compressed.size(),
&uncompressed));
CHECK_EQ(uncompressed, src);
}
TEST(Snappy, IOVecEdgeCases) {
// Test some tricky edge cases in the iovec output that are not necessarily
// exercised by random tests.
// Our output blocks look like this initially (the last iovec is bigger
// than depicted):
// [ ] [ ] [ ] [ ] [ ]
static const int kLengths[] = { 2, 1, 4, 8, 128 };
struct iovec iov[ARRAYSIZE(kLengths)];
for (int i = 0; i < ARRAYSIZE(kLengths); ++i) {
iov[i].iov_base = new char[kLengths[i]];
iov[i].iov_len = kLengths[i];
}
string compressed;
Varint::Append32(&compressed, 22);
// A literal whose output crosses three blocks.
// [ab] [c] [123 ] [ ] [ ]
AppendLiteral(&compressed, "abc123");
// A copy whose output crosses two blocks (source and destination
// segments marked).
// [ab] [c] [1231] [23 ] [ ]
// ^--^ --
AppendCopy(&compressed, 3, 3);
// A copy where the input is, at first, in the block before the output:
//
// [ab] [c] [1231] [231231 ] [ ]
// ^--- ^---
// Then during the copy, the pointers move such that the input and
// output pointers are in the same block:
//
// [ab] [c] [1231] [23123123] [ ]
// ^- ^-
// And then they move again, so that the output pointer is no longer
// in the same block as the input pointer:
// [ab] [c] [1231] [23123123] [123 ]
// ^-- ^--
AppendCopy(&compressed, 6, 9);
// Finally, a copy where the input is from several blocks back,
// and it also crosses three blocks:
//
// [ab] [c] [1231] [23123123] [123b ]
// ^ ^
// [ab] [c] [1231] [23123123] [123bc ]
// ^ ^
// [ab] [c] [1231] [23123123] [123bc12 ]
// ^- ^-
AppendCopy(&compressed, 17, 4);
CHECK(snappy::RawUncompressToIOVec(
compressed.data(), compressed.size(), iov, ARRAYSIZE(iov)));
CHECK_EQ(0, memcmp(iov[0].iov_base, "ab", 2));
CHECK_EQ(0, memcmp(iov[1].iov_base, "c", 1));
CHECK_EQ(0, memcmp(iov[2].iov_base, "1231", 4));
CHECK_EQ(0, memcmp(iov[3].iov_base, "23123123", 8));
CHECK_EQ(0, memcmp(iov[4].iov_base, "123bc12", 7));
for (int i = 0; i < ARRAYSIZE(kLengths); ++i) {
delete[] reinterpret_cast<char *>(iov[i].iov_base);
}
}
TEST(Snappy, IOVecLiteralOverflow) {
static const int kLengths[] = { 3, 4 };
struct iovec iov[ARRAYSIZE(kLengths)];
for (int i = 0; i < ARRAYSIZE(kLengths); ++i) {
iov[i].iov_base = new char[kLengths[i]];
iov[i].iov_len = kLengths[i];
}
string compressed;
Varint::Append32(&compressed, 8);
AppendLiteral(&compressed, "12345678");
CHECK(!snappy::RawUncompressToIOVec(
compressed.data(), compressed.size(), iov, ARRAYSIZE(iov)));
for (int i = 0; i < ARRAYSIZE(kLengths); ++i) {
delete[] reinterpret_cast<char *>(iov[i].iov_base);
}
}
TEST(Snappy, IOVecCopyOverflow) {
static const int kLengths[] = { 3, 4 };
struct iovec iov[ARRAYSIZE(kLengths)];
for (int i = 0; i < ARRAYSIZE(kLengths); ++i) {
iov[i].iov_base = new char[kLengths[i]];
iov[i].iov_len = kLengths[i];
}
string compressed;
Varint::Append32(&compressed, 8);
AppendLiteral(&compressed, "123");
AppendCopy(&compressed, 3, 5);
CHECK(!snappy::RawUncompressToIOVec(
compressed.data(), compressed.size(), iov, ARRAYSIZE(iov)));
for (int i = 0; i < ARRAYSIZE(kLengths); ++i) {
delete[] reinterpret_cast<char *>(iov[i].iov_base);
}
}
static bool CheckUncompressedLength(const string& compressed,
size_t* ulength) {
const bool result1 = snappy::GetUncompressedLength(compressed.data(),
compressed.size(),
ulength);
snappy::ByteArraySource source(compressed.data(), compressed.size());
uint32 length;
const bool result2 = snappy::GetUncompressedLength(&source, &length);
CHECK_EQ(result1, result2);
return result1;
}
TEST(SnappyCorruption, TruncatedVarint) {
string compressed, uncompressed;
size_t ulength;
compressed.push_back('\xf0');
CHECK(!CheckUncompressedLength(compressed, &ulength));
CHECK(!snappy::IsValidCompressedBuffer(compressed.data(), compressed.size()));
CHECK(!snappy::Uncompress(compressed.data(), compressed.size(),
&uncompressed));
}
TEST(SnappyCorruption, UnterminatedVarint) {
string compressed, uncompressed;
size_t ulength;
compressed.push_back('\x80');
compressed.push_back('\x80');
compressed.push_back('\x80');
compressed.push_back('\x80');
compressed.push_back('\x80');
compressed.push_back(10);
CHECK(!CheckUncompressedLength(compressed, &ulength));
CHECK(!snappy::IsValidCompressedBuffer(compressed.data(), compressed.size()));
CHECK(!snappy::Uncompress(compressed.data(), compressed.size(),
&uncompressed));
}
TEST(SnappyCorruption, OverflowingVarint) {
string compressed, uncompressed;
size_t ulength;
compressed.push_back('\xfb');
compressed.push_back('\xff');
compressed.push_back('\xff');
compressed.push_back('\xff');
compressed.push_back('\x7f');
CHECK(!CheckUncompressedLength(compressed, &ulength));
CHECK(!snappy::IsValidCompressedBuffer(compressed.data(), compressed.size()));
CHECK(!snappy::Uncompress(compressed.data(), compressed.size(),
&uncompressed));
}
TEST(Snappy, ReadPastEndOfBuffer) {
// Check that we do not read past end of input
// Make a compressed string that ends with a single-byte literal
string compressed;
Varint::Append32(&compressed, 1);
AppendLiteral(&compressed, "x");
string uncompressed;
DataEndingAtUnreadablePage c(compressed);
CHECK(snappy::Uncompress(c.data(), c.size(), &uncompressed));
CHECK_EQ(uncompressed, string("x"));
}
// Check for an infinite loop caused by a copy with offset==0
TEST(Snappy, ZeroOffsetCopy) {
const char* compressed = "\x40\x12\x00\x00";
// \x40 Length (must be > kMaxIncrementCopyOverflow)
// \x12\x00\x00 Copy with offset==0, length==5
char uncompressed[100];
EXPECT_FALSE(snappy::RawUncompress(compressed, 4, uncompressed));
}
TEST(Snappy, ZeroOffsetCopyValidation) {
const char* compressed = "\x05\x12\x00\x00";
// \x05 Length
// \x12\x00\x00 Copy with offset==0, length==5
EXPECT_FALSE(snappy::IsValidCompressedBuffer(compressed, 4));
}
namespace {
int TestFindMatchLength(const char* s1, const char *s2, unsigned length) {
std::pair<size_t, bool> p =
snappy::internal::FindMatchLength(s1, s2, s2 + length);
CHECK_EQ(p.first < 8, p.second);
return p.first;
}
} // namespace
TEST(Snappy, FindMatchLength) {
// Exercise all different code paths through the function.
// 64-bit version:
// Hit s1_limit in 64-bit loop, hit s1_limit in single-character loop.
EXPECT_EQ(6, TestFindMatchLength("012345", "012345", 6));
EXPECT_EQ(11, TestFindMatchLength("01234567abc", "01234567abc", 11));
// Hit s1_limit in 64-bit loop, find a non-match in single-character loop.
EXPECT_EQ(9, TestFindMatchLength("01234567abc", "01234567axc", 9));
// Same, but edge cases.
EXPECT_EQ(11, TestFindMatchLength("01234567abc!", "01234567abc!", 11));
EXPECT_EQ(11, TestFindMatchLength("01234567abc!", "01234567abc?", 11));
// Find non-match at once in first loop.
EXPECT_EQ(0, TestFindMatchLength("01234567xxxxxxxx", "?1234567xxxxxxxx", 16));
EXPECT_EQ(1, TestFindMatchLength("01234567xxxxxxxx", "0?234567xxxxxxxx", 16));
EXPECT_EQ(4, TestFindMatchLength("01234567xxxxxxxx", "01237654xxxxxxxx", 16));
EXPECT_EQ(7, TestFindMatchLength("01234567xxxxxxxx", "0123456?xxxxxxxx", 16));
// Find non-match in first loop after one block.
EXPECT_EQ(8, TestFindMatchLength("abcdefgh01234567xxxxxxxx",
"abcdefgh?1234567xxxxxxxx", 24));
EXPECT_EQ(9, TestFindMatchLength("abcdefgh01234567xxxxxxxx",
"abcdefgh0?234567xxxxxxxx", 24));
EXPECT_EQ(12, TestFindMatchLength("abcdefgh01234567xxxxxxxx",
"abcdefgh01237654xxxxxxxx", 24));
EXPECT_EQ(15, TestFindMatchLength("abcdefgh01234567xxxxxxxx",
"abcdefgh0123456?xxxxxxxx", 24));
// 32-bit version:
// Short matches.
EXPECT_EQ(0, TestFindMatchLength("01234567", "?1234567", 8));
EXPECT_EQ(1, TestFindMatchLength("01234567", "0?234567", 8));
EXPECT_EQ(2, TestFindMatchLength("01234567", "01?34567", 8));
EXPECT_EQ(3, TestFindMatchLength("01234567", "012?4567", 8));
EXPECT_EQ(4, TestFindMatchLength("01234567", "0123?567", 8));
EXPECT_EQ(5, TestFindMatchLength("01234567", "01234?67", 8));
EXPECT_EQ(6, TestFindMatchLength("01234567", "012345?7", 8));
EXPECT_EQ(7, TestFindMatchLength("01234567", "0123456?", 8));
EXPECT_EQ(7, TestFindMatchLength("01234567", "0123456?", 7));
EXPECT_EQ(7, TestFindMatchLength("01234567!", "0123456??", 7));
// Hit s1_limit in 32-bit loop, hit s1_limit in single-character loop.
EXPECT_EQ(10, TestFindMatchLength("xxxxxxabcd", "xxxxxxabcd", 10));
EXPECT_EQ(10, TestFindMatchLength("xxxxxxabcd?", "xxxxxxabcd?", 10));
EXPECT_EQ(13, TestFindMatchLength("xxxxxxabcdef", "xxxxxxabcdef", 13));
// Same, but edge cases.
EXPECT_EQ(12, TestFindMatchLength("xxxxxx0123abc!", "xxxxxx0123abc!", 12));
EXPECT_EQ(12, TestFindMatchLength("xxxxxx0123abc!", "xxxxxx0123abc?", 12));
// Hit s1_limit in 32-bit loop, find a non-match in single-character loop.
EXPECT_EQ(11, TestFindMatchLength("xxxxxx0123abc", "xxxxxx0123axc", 13));
// Find non-match at once in first loop.
EXPECT_EQ(6, TestFindMatchLength("xxxxxx0123xxxxxxxx",
"xxxxxx?123xxxxxxxx", 18));
EXPECT_EQ(7, TestFindMatchLength("xxxxxx0123xxxxxxxx",
"xxxxxx0?23xxxxxxxx", 18));
EXPECT_EQ(8, TestFindMatchLength("xxxxxx0123xxxxxxxx",
"xxxxxx0132xxxxxxxx", 18));
EXPECT_EQ(9, TestFindMatchLength("xxxxxx0123xxxxxxxx",
"xxxxxx012?xxxxxxxx", 18));
// Same, but edge cases.
EXPECT_EQ(6, TestFindMatchLength("xxxxxx0123", "xxxxxx?123", 10));
EXPECT_EQ(7, TestFindMatchLength("xxxxxx0123", "xxxxxx0?23", 10));
EXPECT_EQ(8, TestFindMatchLength("xxxxxx0123", "xxxxxx0132", 10));
EXPECT_EQ(9, TestFindMatchLength("xxxxxx0123", "xxxxxx012?", 10));
// Find non-match in first loop after one block.
EXPECT_EQ(10, TestFindMatchLength("xxxxxxabcd0123xx",
"xxxxxxabcd?123xx", 16));
EXPECT_EQ(11, TestFindMatchLength("xxxxxxabcd0123xx",
"xxxxxxabcd0?23xx", 16));
EXPECT_EQ(12, TestFindMatchLength("xxxxxxabcd0123xx",
"xxxxxxabcd0132xx", 16));
EXPECT_EQ(13, TestFindMatchLength("xxxxxxabcd0123xx",
"xxxxxxabcd012?xx", 16));
// Same, but edge cases.
EXPECT_EQ(10, TestFindMatchLength("xxxxxxabcd0123", "xxxxxxabcd?123", 14));
EXPECT_EQ(11, TestFindMatchLength("xxxxxxabcd0123", "xxxxxxabcd0?23", 14));
EXPECT_EQ(12, TestFindMatchLength("xxxxxxabcd0123", "xxxxxxabcd0132", 14));
EXPECT_EQ(13, TestFindMatchLength("xxxxxxabcd0123", "xxxxxxabcd012?", 14));
}
TEST(Snappy, FindMatchLengthRandom) {
constexpr int kNumTrials = 10000;
constexpr int kTypicalLength = 10;
std::minstd_rand0 rng(FLAGS_test_random_seed);
std::uniform_int_distribution<int> uniform_byte(0, 255);
std::bernoulli_distribution one_in_two(1.0 / 2);
std::bernoulli_distribution one_in_typical_length(1.0 / kTypicalLength);
for (int i = 0; i < kNumTrials; i++) {
string s, t;
char a = static_cast<char>(uniform_byte(rng));
char b = static_cast<char>(uniform_byte(rng));
while (!one_in_typical_length(rng)) {
s.push_back(one_in_two(rng) ? a : b);
t.push_back(one_in_two(rng) ? a : b);
}
DataEndingAtUnreadablePage u(s);
DataEndingAtUnreadablePage v(t);
int matched = TestFindMatchLength(u.data(), v.data(), t.size());
if (matched == t.size()) {
EXPECT_EQ(s, t);
} else {
EXPECT_NE(s[matched], t[matched]);
for (int j = 0; j < matched; j++) {
EXPECT_EQ(s[j], t[j]);
}
}
}
}
static uint16 MakeEntry(unsigned int extra,
unsigned int len,
unsigned int copy_offset) {
// Check that all of the fields fit within the allocated space
assert(extra == (extra & 0x7)); // At most 3 bits
assert(copy_offset == (copy_offset & 0x7)); // At most 3 bits
assert(len == (len & 0x7f)); // At most 7 bits
return len | (copy_offset << 8) | (extra << 11);
}
// Check that the decompression table is correct, and optionally print out
// the computed one.
TEST(Snappy, VerifyCharTable) {
using snappy::internal::LITERAL;
using snappy::internal::COPY_1_BYTE_OFFSET;
using snappy::internal::COPY_2_BYTE_OFFSET;
using snappy::internal::COPY_4_BYTE_OFFSET;
using snappy::internal::char_table;
uint16 dst[256];
// Place invalid entries in all places to detect missing initialization
int assigned = 0;
for (int i = 0; i < 256; i++) {
dst[i] = 0xffff;
}
// Small LITERAL entries. We store (len-1) in the top 6 bits.
for (unsigned int len = 1; len <= 60; len++) {
dst[LITERAL | ((len-1) << 2)] = MakeEntry(0, len, 0);
assigned++;
}
// Large LITERAL entries. We use 60..63 in the high 6 bits to
// encode the number of bytes of length info that follow the opcode.
for (unsigned int extra_bytes = 1; extra_bytes <= 4; extra_bytes++) {
// We set the length field in the lookup table to 1 because extra
// bytes encode len-1.
dst[LITERAL | ((extra_bytes+59) << 2)] = MakeEntry(extra_bytes, 1, 0);
assigned++;
}
// COPY_1_BYTE_OFFSET.
//
// The tag byte in the compressed data stores len-4 in 3 bits, and
// offset/256 in 5 bits. offset%256 is stored in the next byte.
//
// This format is used for length in range [4..11] and offset in
// range [0..2047]
for (unsigned int len = 4; len < 12; len++) {
for (unsigned int offset = 0; offset < 2048; offset += 256) {
dst[COPY_1_BYTE_OFFSET | ((len-4)<<2) | ((offset>>8)<<5)] =
MakeEntry(1, len, offset>>8);
assigned++;
}
}
// COPY_2_BYTE_OFFSET.
// Tag contains len-1 in top 6 bits, and offset in next two bytes.
for (unsigned int len = 1; len <= 64; len++) {
dst[COPY_2_BYTE_OFFSET | ((len-1)<<2)] = MakeEntry(2, len, 0);
assigned++;
}
// COPY_4_BYTE_OFFSET.
// Tag contents len-1 in top 6 bits, and offset in next four bytes.
for (unsigned int len = 1; len <= 64; len++) {
dst[COPY_4_BYTE_OFFSET | ((len-1)<<2)] = MakeEntry(4, len, 0);
assigned++;
}
// Check that each entry was initialized exactly once.
EXPECT_EQ(256, assigned) << "Assigned only " << assigned << " of 256";
for (int i = 0; i < 256; i++) {
EXPECT_NE(0xffff, dst[i]) << "Did not assign byte " << i;
}
if (FLAGS_snappy_dump_decompression_table) {
printf("static const uint16 char_table[256] = {\n ");
for (int i = 0; i < 256; i++) {
printf("0x%04x%s",
dst[i],
((i == 255) ? "\n" : (((i%8) == 7) ? ",\n " : ", ")));
}
printf("};\n");
}
// Check that computed table matched recorded table.
for (int i = 0; i < 256; i++) {
EXPECT_EQ(dst[i], char_table[i]) << "Mismatch in byte " << i;
}
}
static void CompressFile(const char* fname) {
string fullinput;
CHECK_OK(file::GetContents(fname, &fullinput, file::Defaults()));
string compressed;
Compress(fullinput.data(), fullinput.size(), SNAPPY, &compressed, false);
CHECK_OK(file::SetContents(string(fname).append(".comp"), compressed,
file::Defaults()));
}
static void UncompressFile(const char* fname) {
string fullinput;
CHECK_OK(file::GetContents(fname, &fullinput, file::Defaults()));
size_t uncompLength;
CHECK(CheckUncompressedLength(fullinput, &uncompLength));
string uncompressed;
uncompressed.resize(uncompLength);
CHECK(snappy::Uncompress(fullinput.data(), fullinput.size(), &uncompressed));
CHECK_OK(file::SetContents(string(fname).append(".uncomp"), uncompressed,
file::Defaults()));
}
static void MeasureFile(const char* fname) {
string fullinput;
CHECK_OK(file::GetContents(fname, &fullinput, file::Defaults()));
printf("%-40s :\n", fname);
int start_len = (FLAGS_start_len < 0) ? fullinput.size() : FLAGS_start_len;
int end_len = fullinput.size();
if (FLAGS_end_len >= 0) {
end_len = std::min<int>(fullinput.size(), FLAGS_end_len);
}
for (int len = start_len; len <= end_len; len++) {
const char* const input = fullinput.data();
int repeats = (FLAGS_bytes + len) / (len + 1);
if (FLAGS_zlib) Measure(input, len, ZLIB, repeats, 1024<<10);
if (FLAGS_lzo) Measure(input, len, LZO, repeats, 1024<<10);
if (FLAGS_snappy) Measure(input, len, SNAPPY, repeats, 4096<<10);
// For block-size based measurements
if (0 && FLAGS_snappy) {
Measure(input, len, SNAPPY, repeats, 8<<10);
Measure(input, len, SNAPPY, repeats, 16<<10);
Measure(input, len, SNAPPY, repeats, 32<<10);
Measure(input, len, SNAPPY, repeats, 64<<10);
Measure(input, len, SNAPPY, repeats, 256<<10);
Measure(input, len, SNAPPY, repeats, 1024<<10);
}
}
}
static struct {
const char* label;
const char* filename;
size_t size_limit;
} files[] = {
{ "html", "html", 0 },
{ "urls", "urls.10K", 0 },
{ "jpg", "fireworks.jpeg", 0 },
{ "jpg_200", "fireworks.jpeg", 200 },
{ "pdf", "paper-100k.pdf", 0 },
{ "html4", "html_x_4", 0 },
{ "txt1", "alice29.txt", 0 },
{ "txt2", "asyoulik.txt", 0 },
{ "txt3", "lcet10.txt", 0 },
{ "txt4", "plrabn12.txt", 0 },
{ "pb", "geo.protodata", 0 },
{ "gaviota", "kppkn.gtb", 0 },
};
static void BM_UFlat(int iters, int arg) {
StopBenchmarkTiming();
// Pick file to process based on "arg"
CHECK_GE(arg, 0);
CHECK_LT(arg, ARRAYSIZE(files));
string contents = ReadTestDataFile(files[arg].filename,
files[arg].size_limit);
string zcontents;
snappy::Compress(contents.data(), contents.size(), &zcontents);
char* dst = new char[contents.size()];
SetBenchmarkBytesProcessed(static_cast<int64>(iters) *
static_cast<int64>(contents.size()));
SetBenchmarkLabel(files[arg].label);
StartBenchmarkTiming();
while (iters-- > 0) {
CHECK(snappy::RawUncompress(zcontents.data(), zcontents.size(), dst));
}
StopBenchmarkTiming();
delete[] dst;
}
BENCHMARK(BM_UFlat)->DenseRange(0, ARRAYSIZE(files) - 1);
static void BM_UValidate(int iters, int arg) {
StopBenchmarkTiming();
// Pick file to process based on "arg"
CHECK_GE(arg, 0);
CHECK_LT(arg, ARRAYSIZE(files));
string contents = ReadTestDataFile(files[arg].filename,
files[arg].size_limit);
string zcontents;
snappy::Compress(contents.data(), contents.size(), &zcontents);
SetBenchmarkBytesProcessed(static_cast<int64>(iters) *
static_cast<int64>(contents.size()));
SetBenchmarkLabel(files[arg].label);
StartBenchmarkTiming();
while (iters-- > 0) {
CHECK(snappy::IsValidCompressedBuffer(zcontents.data(), zcontents.size()));
}
StopBenchmarkTiming();
}
BENCHMARK(BM_UValidate)->DenseRange(0, 4);
static void BM_UIOVec(int iters, int arg) {
StopBenchmarkTiming();
// Pick file to process based on "arg"
CHECK_GE(arg, 0);
CHECK_LT(arg, ARRAYSIZE(files));
string contents = ReadTestDataFile(files[arg].filename,
files[arg].size_limit);
string zcontents;
snappy::Compress(contents.data(), contents.size(), &zcontents);
// Uncompress into an iovec containing ten entries.
const int kNumEntries = 10;
struct iovec iov[kNumEntries];
char *dst = new char[contents.size()];
int used_so_far = 0;
for (int i = 0; i < kNumEntries; ++i) {
iov[i].iov_base = dst + used_so_far;
if (used_so_far == contents.size()) {
iov[i].iov_len = 0;
continue;
}
if (i == kNumEntries - 1) {
iov[i].iov_len = contents.size() - used_so_far;
} else {
iov[i].iov_len = contents.size() / kNumEntries;
}
used_so_far += iov[i].iov_len;
}
SetBenchmarkBytesProcessed(static_cast<int64>(iters) *
static_cast<int64>(contents.size()));
SetBenchmarkLabel(files[arg].label);
StartBenchmarkTiming();
while (iters-- > 0) {
CHECK(snappy::RawUncompressToIOVec(zcontents.data(), zcontents.size(), iov,
kNumEntries));
}
StopBenchmarkTiming();
delete[] dst;
}
BENCHMARK(BM_UIOVec)->DenseRange(0, 4);
static void BM_UFlatSink(int iters, int arg) {
StopBenchmarkTiming();
// Pick file to process based on "arg"
CHECK_GE(arg, 0);
CHECK_LT(arg, ARRAYSIZE(files));
string contents = ReadTestDataFile(files[arg].filename,
files[arg].size_limit);
string zcontents;
snappy::Compress(contents.data(), contents.size(), &zcontents);
char* dst = new char[contents.size()];
SetBenchmarkBytesProcessed(static_cast<int64>(iters) *
static_cast<int64>(contents.size()));
SetBenchmarkLabel(files[arg].label);
StartBenchmarkTiming();
while (iters-- > 0) {
snappy::ByteArraySource source(zcontents.data(), zcontents.size());
snappy::UncheckedByteArraySink sink(dst);
CHECK(snappy::Uncompress(&source, &sink));
}
StopBenchmarkTiming();
string s(dst, contents.size());
CHECK_EQ(contents, s);
delete[] dst;
}
BENCHMARK(BM_UFlatSink)->DenseRange(0, ARRAYSIZE(files) - 1);
static void BM_ZFlat(int iters, int arg) {
StopBenchmarkTiming();
// Pick file to process based on "arg"
CHECK_GE(arg, 0);
CHECK_LT(arg, ARRAYSIZE(files));
string contents = ReadTestDataFile(files[arg].filename,
files[arg].size_limit);
char* dst = new char[snappy::MaxCompressedLength(contents.size())];
SetBenchmarkBytesProcessed(static_cast<int64>(iters) *
static_cast<int64>(contents.size()));
StartBenchmarkTiming();
size_t zsize = 0;
while (iters-- > 0) {
snappy::RawCompress(contents.data(), contents.size(), dst, &zsize);
}
StopBenchmarkTiming();
const double compression_ratio =
static_cast<double>(zsize) / std::max<size_t>(1, contents.size());
SetBenchmarkLabel(StringPrintf("%s (%.2f %%)",
files[arg].label, 100.0 * compression_ratio));
VLOG(0) << StringPrintf("compression for %s: %zd -> %zd bytes",
files[arg].label, contents.size(), zsize);
delete[] dst;
}
BENCHMARK(BM_ZFlat)->DenseRange(0, ARRAYSIZE(files) - 1);
} // namespace snappy
int main(int argc, char** argv) {
InitGoogle(argv[0], &argc, &argv, true);
RunSpecifiedBenchmarks();
if (argc >= 2) {
for (int arg = 1; arg < argc; arg++) {
if (FLAGS_write_compressed) {
snappy::CompressFile(argv[arg]);
} else if (FLAGS_write_uncompressed) {
snappy::UncompressFile(argv[arg]);
} else {
snappy::MeasureFile(argv[arg]);
}
}
return 0;
}
return RUN_ALL_TESTS();
}
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