Merge pull request #13 from huachaohuang/patch-1
Allow to compile in nested packages.
diff --git a/README b/README
index 3bc8888..c60dab9 100644
--- a/README
+++ b/README
@@ -29,7 +29,7 @@
Performance
===========
-
+
Snappy is intended to be fast. On a single core of a Core i7 processor
in 64-bit mode, it compresses at about 250 MB/sec or more and decompresses at
about 500 MB/sec or more. (These numbers are for the slowest inputs in our
@@ -67,7 +67,7 @@
Note that Snappy, both the implementation and the main interface,
is written in C++. However, several third-party bindings to other languages
-are available; see the Google Code page at http://code.google.com/p/snappy/
+are available; see the home page at http://google.github.io/snappy/
for more information. Also, if you want to use Snappy from C code, you can
use the included C bindings in snappy-c.h.
@@ -102,12 +102,12 @@
Google Test library installed, unit test behavior (especially failures) will be
significantly more user-friendly. You can find Google Test at
- http://code.google.com/p/googletest/
+ http://github.com/google/googletest
You probably also want the gflags library for handling of command-line flags;
you can find it at
- http://code.google.com/p/google-gflags/
+ http://gflags.github.io/gflags/
In addition to the unit tests, snappy contains microbenchmarks used to
tune compression and decompression performance. These are automatically run
@@ -129,7 +129,11 @@
Contact
=======
-Snappy is distributed through Google Code. For the latest version, a bug tracker,
+Snappy is distributed through GitHub. For the latest version, a bug tracker,
and other information, see
- http://code.google.com/p/snappy/
+ http://google.github.io/snappy/
+
+or the repository at
+
+ https://github.com/google/snappy
diff --git a/autogen.sh b/autogen.sh
index 9d0ebe9..9cb502e 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -2,6 +2,11 @@
rm -rf autom4te.cache
aclocal -I m4
autoheader
-libtoolize --copy
+if glibtoolize --version >/dev/null 2>/dev/null; then
+ LIBTOOLIZE=${LIBTOOLIZE:-glibtoolize}
+else
+ LIBTOOLIZE=${LIBTOOLIZE:-libtoolize}
+fi
+$LIBTOOLIZE --copy
automake --add-missing --copy
autoconf
diff --git a/snappy-stubs-internal.h b/snappy-stubs-internal.h
index ddca1a8..1954c63 100644
--- a/snappy-stubs-internal.h
+++ b/snappy-stubs-internal.h
@@ -116,6 +116,15 @@
// sub-architectures.
//
// This is a mess, but there's not much we can do about it.
+//
+// To further complicate matters, only LDR instructions (single reads) are
+// allowed to be unaligned, not LDRD (two reads) or LDM (many reads). Unless we
+// explicitly tell the compiler that these accesses can be unaligned, it can and
+// will combine accesses. On armcc, the way to signal this is done by accessing
+// through the type (uint32 __packed *), but GCC has no such attribute
+// (it ignores __attribute__((packed)) on individual variables). However,
+// we can tell it that a _struct_ is unaligned, which has the same effect,
+// so we do that.
#elif defined(__arm__) && \
!defined(__ARM_ARCH_4__) && \
@@ -131,11 +140,39 @@
!defined(__ARM_ARCH_6ZK__) && \
!defined(__ARM_ARCH_6T2__)
-#define UNALIGNED_LOAD16(_p) (*reinterpret_cast<const uint16 *>(_p))
-#define UNALIGNED_LOAD32(_p) (*reinterpret_cast<const uint32 *>(_p))
+#if __GNUC__
+#define ATTRIBUTE_PACKED __attribute__((__packed__))
+#else
+#define ATTRIBUTE_PACKED
+#endif
-#define UNALIGNED_STORE16(_p, _val) (*reinterpret_cast<uint16 *>(_p) = (_val))
-#define UNALIGNED_STORE32(_p, _val) (*reinterpret_cast<uint32 *>(_p) = (_val))
+namespace base {
+namespace internal {
+
+struct Unaligned16Struct {
+ uint16 value;
+ uint8 dummy; // To make the size non-power-of-two.
+} ATTRIBUTE_PACKED;
+
+struct Unaligned32Struct {
+ uint32 value;
+ uint8 dummy; // To make the size non-power-of-two.
+} ATTRIBUTE_PACKED;
+
+} // namespace internal
+} // namespace base
+
+#define UNALIGNED_LOAD16(_p) \
+ ((reinterpret_cast<const ::snappy::base::internal::Unaligned16Struct *>(_p))->value)
+#define UNALIGNED_LOAD32(_p) \
+ ((reinterpret_cast<const ::snappy::base::internal::Unaligned32Struct *>(_p))->value)
+
+#define UNALIGNED_STORE16(_p, _val) \
+ ((reinterpret_cast< ::snappy::base::internal::Unaligned16Struct *>(_p))->value = \
+ (_val))
+#define UNALIGNED_STORE32(_p, _val) \
+ ((reinterpret_cast< ::snappy::base::internal::Unaligned32Struct *>(_p))->value = \
+ (_val))
// TODO(user): NEON supports unaligned 64-bit loads and stores.
// See if that would be more efficient on platforms supporting it,
diff --git a/snappy-test.h b/snappy-test.h
index dbc55b9..5fb09c7 100644
--- a/snappy-test.h
+++ b/snappy-test.h
@@ -196,6 +196,7 @@
void Test_Snappy_FourByteOffset();
void Test_SnappyCorruption_TruncatedVarint();
void Test_SnappyCorruption_UnterminatedVarint();
+void Test_SnappyCorruption_OverflowingVarint();
void Test_Snappy_ReadPastEndOfBuffer();
void Test_Snappy_FindMatchLength();
void Test_Snappy_FindMatchLengthRandom();
@@ -500,6 +501,7 @@
snappy::Test_Snappy_FourByteOffset();
snappy::Test_SnappyCorruption_TruncatedVarint();
snappy::Test_SnappyCorruption_UnterminatedVarint();
+ snappy::Test_SnappyCorruption_OverflowingVarint();
snappy::Test_Snappy_ReadPastEndOfBuffer();
snappy::Test_Snappy_FindMatchLength();
snappy::Test_Snappy_FindMatchLengthRandom();
diff --git a/snappy.cc b/snappy.cc
index d81e6b3..8a3668c 100644
--- a/snappy.cc
+++ b/snappy.cc
@@ -364,9 +364,9 @@
//
// Heuristic match skipping: If 32 bytes are scanned with no matches
// found, start looking only at every other byte. If 32 more bytes are
- // scanned, look at every third byte, etc.. When a match is found,
- // immediately go back to looking at every byte. This is a small loss
- // (~5% performance, ~0.1% density) for compressible data due to more
+ // scanned (or skipped), look at every third byte, etc.. When a match is
+ // found, immediately go back to looking at every byte. This is a small
+ // loss (~5% performance, ~0.1% density) for compressible data due to more
// bookkeeping, but for non-compressible data (such as JPEG) it's a huge
// win since the compressor quickly "realizes" the data is incompressible
// and doesn't bother looking for matches everywhere.
@@ -382,7 +382,8 @@
ip = next_ip;
uint32 hash = next_hash;
assert(hash == Hash(ip, shift));
- uint32 bytes_between_hash_lookups = skip++ >> 5;
+ uint32 bytes_between_hash_lookups = skip >> 5;
+ skip += bytes_between_hash_lookups;
next_ip = ip + bytes_between_hash_lookups;
if (PREDICT_FALSE(next_ip > ip_limit)) {
goto emit_remainder;
@@ -545,7 +546,9 @@
if (n == 0) return false;
const unsigned char c = *(reinterpret_cast<const unsigned char*>(ip));
reader_->Skip(1);
- *result |= static_cast<uint32>(c & 0x7f) << shift;
+ uint32 val = c & 0x7f;
+ if (((val << shift) >> shift) != val) return false;
+ *result |= val << shift;
if (c < 128) {
break;
}
diff --git a/snappy_unittest.cc b/snappy_unittest.cc
index 3081662..65ac16a 100644
--- a/snappy_unittest.cc
+++ b/snappy_unittest.cc
@@ -1007,6 +1007,20 @@
&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