| // 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 <algorithm> |
| #include <cmath> |
| #include <cstdlib> |
| #include <random> |
| #include <string> |
| #include <utility> |
| #include <vector> |
| |
| #include "snappy-test.h" |
| |
| #include "gtest/gtest.h" |
| |
| #include "snappy-internal.h" |
| #include "snappy-sinksource.h" |
| #include "snappy.h" |
| #include "snappy_test_data.h" |
| |
| SNAPPY_FLAG(bool, snappy_dump_decompression_table, false, |
| "If true, we print the decompression table during tests."); |
| |
| namespace snappy { |
| |
| namespace { |
| |
| #if HAVE_FUNC_MMAP && 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 std::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; |
| std::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 // HAVE_FUNC_MMAP) && HAVE_FUNC_SYSCONF |
| |
| // Fallback for systems without mmap. |
| using DataEndingAtUnreadablePage = std::string; |
| |
| #endif |
| |
| int VerifyString(const std::string& input) { |
| std::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())); |
| |
| std::string uncompressed; |
| DataEndingAtUnreadablePage c(compressed); |
| CHECK(snappy::Uncompress(c.data(), c.size(), &uncompressed)); |
| CHECK_EQ(uncompressed, input); |
| return uncompressed.size(); |
| } |
| |
| void VerifyStringSink(const std::string& input) { |
| std::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())); |
| |
| std::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); |
| } |
| |
| struct iovec* GetIOVec(const std::string& input, char*& buf, size_t& num) { |
| std::minstd_rand0 rng(input.size()); |
| std::uniform_int_distribution<size_t> uniform_1_to_10(1, 10); |
| num = uniform_1_to_10(rng); |
| if (input.size() < num) { |
| num = input.size(); |
| } |
| struct iovec* iov = new iovec[num]; |
| size_t 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; |
| } |
| return iov; |
| } |
| |
| int VerifyIOVecSource(const std::string& input) { |
| std::string compressed; |
| std::string copy = input; |
| char* buf = const_cast<char*>(copy.data()); |
| size_t num = 0; |
| struct iovec* iov = GetIOVec(input, buf, num); |
| const size_t written = snappy::CompressFromIOVec(iov, num, &compressed); |
| CHECK_EQ(written, compressed.size()); |
| CHECK_LE(compressed.size(), snappy::MaxCompressedLength(input.size())); |
| CHECK(snappy::IsValidCompressedBuffer(compressed.data(), compressed.size())); |
| |
| std::string uncompressed; |
| DataEndingAtUnreadablePage c(compressed); |
| CHECK(snappy::Uncompress(c.data(), c.size(), &uncompressed)); |
| CHECK_EQ(uncompressed, input); |
| delete[] iov; |
| return uncompressed.size(); |
| } |
| |
| void VerifyIOVecSink(const std::string& input) { |
| std::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())); |
| char* buf = new char[input.size()]; |
| size_t num = 0; |
| struct iovec* iov = GetIOVec(input, buf, num); |
| 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. |
| void VerifyNonBlockedCompression(const std::string& input) { |
| if (input.length() > snappy::kBlockSize) { |
| // We cannot test larger blocks than the maximum block size, obviously. |
| return; |
| } |
| |
| std::string prefix; |
| Varint::Append32(&prefix, input.size()); |
| |
| // Setup compression table |
| snappy::internal::WorkingMemory wmem(input.size()); |
| int table_size; |
| uint16_t* table = wmem.GetHashTable(input.size(), &table_size); |
| |
| // Compress entire input in one shot |
| std::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 std::string |
| std::string uncomp_str; |
| CHECK(snappy::Uncompress(compressed.data(), compressed.size(), &uncomp_str)); |
| CHECK_EQ(uncomp_str, input); |
| |
| // Uncompress using source/sink |
| std::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; |
| std::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(std::string(iovec_data.data(), input.size()), input); |
| } |
| } |
| |
| // Expand the input so that it is at least K times as big as block size |
| std::string Expand(const std::string& input) { |
| static const int K = 3; |
| std::string data = input; |
| while (data.size() < K * snappy::kBlockSize) { |
| data += input; |
| } |
| return data; |
| } |
| |
| int Verify(const std::string& input) { |
| VLOG(1) << "Verifying input of size " << input.size(); |
| |
| // Compress using string based routines |
| const int result = VerifyString(input); |
| |
| // Compress using `iovec`-based routines. |
| CHECK_EQ(VerifyIOVecSource(input), result); |
| |
| // Verify using sink based routines |
| VerifyStringSink(input); |
| |
| VerifyNonBlockedCompression(input); |
| VerifyIOVecSink(input); |
| if (!input.empty()) { |
| const std::string expanded = Expand(input); |
| VerifyNonBlockedCompression(expanded); |
| VerifyIOVecSink(input); |
| } |
| |
| return result; |
| } |
| |
| bool IsValidCompressedBuffer(const std::string& c) { |
| return snappy::IsValidCompressedBuffer(c.data(), c.size()); |
| } |
| bool Uncompress(const std::string& c, std::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) { |
| std::string source = "making sure we don't crash with corrupted input"; |
| VLOG(1) << source; |
| std::string dest; |
| std::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 (char& source_char : source) { |
| source_char = '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) { |
| std::string data = |
| ReadTestDataFile(StrFormat("baddata%d.snappy", i).c_str(), 0); |
| std::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_t 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. |
| void AppendLiteral(std::string* dst, const std::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 += std::string(number, count); |
| } |
| *dst += literal; |
| } |
| |
| void AppendCopy(std::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" + std::string(16, 'b') + std::string("aaaaa") + "abc"); |
| Verify("aaaaaaa" + std::string(256, 'b') + std::string("aaaaa") + "abc"); |
| Verify("aaaaaaa" + std::string(2047, 'b') + std::string("aaaaa") + "abc"); |
| Verify("aaaaaaa" + std::string(65536, 'b') + std::string("aaaaa") + "abc"); |
| Verify("abcaaaaaaa" + std::string(65536, 'b') + std::string("aaaaa") + "abc"); |
| } |
| |
| // Regression test for cr/345340892. |
| TEST(Snappy, AppendSelfPatternExtensionEdgeCases) { |
| Verify("abcabcabcabcabcabcab"); |
| Verify("abcabcabcabcabcabcab0123456789ABCDEF"); |
| |
| Verify("abcabcabcabcabcabcabcabcabcabcabcabc"); |
| Verify("abcabcabcabcabcabcabcabcabcabcabcabc0123456789ABCDEF"); |
| } |
| |
| // Regression test for cr/345340892. |
| TEST(Snappy, AppendSelfPatternExtensionEdgeCasesExhaustive) { |
| std::mt19937 rng; |
| std::uniform_int_distribution<int> uniform_byte(0, 255); |
| for (int pattern_size = 1; pattern_size <= 18; ++pattern_size) { |
| for (int length = 1; length <= 64; ++length) { |
| for (int extra_bytes_after_pattern : {0, 1, 15, 16, 128}) { |
| const int size = pattern_size + length + extra_bytes_after_pattern; |
| std::string input; |
| input.resize(size); |
| for (int i = 0; i < pattern_size; ++i) { |
| input[i] = 'a' + i; |
| } |
| for (int i = 0; i < length; ++i) { |
| input[pattern_size + i] = input[i]; |
| } |
| for (int i = 0; i < extra_bytes_after_pattern; ++i) { |
| input[pattern_size + length + i] = |
| static_cast<char>(uniform_byte(rng)); |
| } |
| Verify(input); |
| } |
| } |
| } |
| } |
| |
| // Verify max blowup (lots of four-byte copies) |
| TEST(Snappy, MaxBlowup) { |
| std::mt19937 rng; |
| std::uniform_int_distribution<int> uniform_byte(0, 255); |
| std::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) { |
| std::string four_bytes(input.end() - i - 4, input.end() - i); |
| input.append(four_bytes); |
| } |
| Verify(input); |
| } |
| |
| TEST(Snappy, RandomData) { |
| std::minstd_rand0 rng(snappy::GetFlag(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; |
| } |
| |
| std::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. |
| std::string fragment1 = "012345689abcdefghijklmnopqrstuvwxyz"; |
| std::string fragment2 = "some other string"; |
| |
| // How many times each fragment is emitted. |
| const int n1 = 2; |
| const int n2 = 100000 / fragment2.size(); |
| const size_t length = n1 * fragment1.size() + n2 * fragment2.size(); |
| |
| std::string compressed; |
| Varint::Append32(&compressed, length); |
| |
| AppendLiteral(&compressed, fragment1); |
| std::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()); |
| |
| std::string uncompressed; |
| CHECK(snappy::IsValidCompressedBuffer(compressed.data(), compressed.size())); |
| CHECK(snappy::Uncompress(compressed.data(), compressed.size(), |
| &uncompressed)); |
| CHECK_EQ(uncompressed, src); |
| } |
| |
| TEST(Snappy, IOVecSourceEdgeCases) { |
| // Validate that empty leading, trailing, and in-between iovecs are handled: |
| // [] [] ['a'] [] ['b'] []. |
| std::string data = "ab"; |
| char* buf = const_cast<char*>(data.data()); |
| size_t used_so_far = 0; |
| static const int kLengths[] = {0, 0, 1, 0, 1, 0}; |
| struct iovec iov[ARRAYSIZE(kLengths)]; |
| for (int i = 0; i < ARRAYSIZE(kLengths); ++i) { |
| iov[i].iov_base = buf + used_so_far; |
| iov[i].iov_len = kLengths[i]; |
| used_so_far += kLengths[i]; |
| } |
| std::string compressed; |
| snappy::CompressFromIOVec(iov, ARRAYSIZE(kLengths), &compressed); |
| std::string uncompressed; |
| snappy::Uncompress(compressed.data(), compressed.size(), &uncompressed); |
| CHECK_EQ(data, uncompressed); |
| } |
| |
| TEST(Snappy, IOVecSinkEdgeCases) { |
| // 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]; |
| } |
| |
| std::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]; |
| } |
| |
| std::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]; |
| } |
| |
| std::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); |
| } |
| } |
| |
| bool CheckUncompressedLength(const std::string& compressed, size_t* ulength) { |
| const bool result1 = snappy::GetUncompressedLength(compressed.data(), |
| compressed.size(), |
| ulength); |
| |
| snappy::ByteArraySource source(compressed.data(), compressed.size()); |
| uint32_t length; |
| const bool result2 = snappy::GetUncompressedLength(&source, &length); |
| CHECK_EQ(result1, result2); |
| return result1; |
| } |
| |
| TEST(SnappyCorruption, TruncatedVarint) { |
| std::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) { |
| std::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) { |
| std::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 |
| std::string compressed; |
| Varint::Append32(&compressed, 1); |
| AppendLiteral(&compressed, "x"); |
| |
| std::string uncompressed; |
| DataEndingAtUnreadablePage c(compressed); |
| CHECK(snappy::Uncompress(c.data(), c.size(), &uncompressed)); |
| CHECK_EQ(uncompressed, std::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)); |
| } |
| |
| int TestFindMatchLength(const char* s1, const char *s2, unsigned length) { |
| uint64_t data; |
| std::pair<size_t, bool> p = |
| snappy::internal::FindMatchLength(s1, s2, s2 + length, &data); |
| CHECK_EQ(p.first < 8, p.second); |
| return p.first; |
| } |
| |
| 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(snappy::GetFlag(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) { |
| std::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); |
| size_t matched = TestFindMatchLength(u.data(), v.data(), t.size()); |
| if (matched == t.size()) { |
| EXPECT_EQ(s, t); |
| } else { |
| EXPECT_NE(s[matched], t[matched]); |
| for (size_t j = 0; j < matched; ++j) { |
| EXPECT_EQ(s[j], t[j]); |
| } |
| } |
| } |
| } |
| |
| uint16_t 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_t 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 (uint8_t 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 (uint8_t 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 3 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 (uint8_t len = 4; len < 12; ++len) { |
| for (uint16_t offset = 0; offset < 2048; offset += 256) { |
| uint8_t offset_high = static_cast<uint8_t>(offset >> 8); |
| dst[COPY_1_BYTE_OFFSET | ((len - 4) << 2) | (offset_high << 5)] = |
| MakeEntry(1, len, offset_high); |
| assigned++; |
| } |
| } |
| |
| // COPY_2_BYTE_OFFSET. |
| // Tag contains len-1 in top 6 bits, and offset in next two bytes. |
| for (uint8_t 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 (uint8_t 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 (snappy::GetFlag(FLAGS_snappy_dump_decompression_table)) { |
| std::printf("static const uint16_t char_table[256] = {\n "); |
| for (int i = 0; i < 256; ++i) { |
| std::printf("0x%04x%s", |
| dst[i], |
| ((i == 255) ? "\n" : (((i % 8) == 7) ? ",\n " : ", "))); |
| } |
| std::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; |
| } |
| } |
| |
| TEST(Snappy, TestBenchmarkFiles) { |
| for (int i = 0; i < ARRAYSIZE(kTestDataFiles); ++i) { |
| Verify(ReadTestDataFile(kTestDataFiles[i].filename, |
| kTestDataFiles[i].size_limit)); |
| } |
| } |
| |
| } // namespace |
| |
| } // namespace snappy |