aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--src/serialization.cpp20
-rw-r--r--src/serialization.h2
-rw-r--r--src/unittest/test_compression.cpp63
3 files changed, 81 insertions, 4 deletions
diff --git a/src/serialization.cpp b/src/serialization.cpp
index 36ddb467c..310604f54 100644
--- a/src/serialization.cpp
+++ b/src/serialization.cpp
@@ -99,7 +99,7 @@ void compressZlib(const std::string &data, std::ostream &os, int level)
compressZlib((u8*)data.c_str(), data.size(), os, level);
}
-void decompressZlib(std::istream &is, std::ostream &os)
+void decompressZlib(std::istream &is, std::ostream &os, size_t limit)
{
z_stream z;
const s32 bufsize = 16384;
@@ -108,6 +108,7 @@ void decompressZlib(std::istream &is, std::ostream &os)
int status = 0;
int ret;
int bytes_read = 0;
+ int bytes_written = 0;
int input_buffer_len = 0;
z.zalloc = Z_NULL;
@@ -124,8 +125,20 @@ void decompressZlib(std::istream &is, std::ostream &os)
for(;;)
{
+ int output_size = bufsize;
z.next_out = (Bytef*)output_buffer;
- z.avail_out = bufsize;
+ z.avail_out = output_size;
+
+ if (limit) {
+ int limit_remaining = limit - bytes_written;
+ if (limit_remaining <= 0) {
+ // we're aborting ahead of time - throw an error?
+ break;
+ }
+ if (limit_remaining < output_size) {
+ z.avail_out = output_size = limit_remaining;
+ }
+ }
if(z.avail_in == 0)
{
@@ -153,10 +166,11 @@ void decompressZlib(std::istream &is, std::ostream &os)
zerr(status);
throw SerializationError("decompressZlib: inflate failed");
}
- int count = bufsize - z.avail_out;
+ int count = output_size - z.avail_out;
//dstream<<"count="<<count<<std::endl;
if(count)
os.write(output_buffer, count);
+ bytes_written += count;
if(status == Z_STREAM_END)
{
//dstream<<"Z_STREAM_END"<<std::endl;
diff --git a/src/serialization.h b/src/serialization.h
index 7f8b83382..f399983c4 100644
--- a/src/serialization.h
+++ b/src/serialization.h
@@ -87,7 +87,7 @@ inline bool ser_ver_supported(s32 v) {
void compressZlib(const u8 *data, size_t data_size, std::ostream &os, int level = -1);
void compressZlib(const std::string &data, std::ostream &os, int level = -1);
-void decompressZlib(std::istream &is, std::ostream &os);
+void decompressZlib(std::istream &is, std::ostream &os, size_t limit = 0);
// These choose between zlib and a self-made one according to version
void compress(const SharedBuffer<u8> &data, std::ostream &os, u8 version);
diff --git a/src/unittest/test_compression.cpp b/src/unittest/test_compression.cpp
index 7d0378131..dfcadd4b2 100644
--- a/src/unittest/test_compression.cpp
+++ b/src/unittest/test_compression.cpp
@@ -37,6 +37,8 @@ public:
void testRLECompression();
void testZlibCompression();
void testZlibLargeData();
+ void testZlibLimit();
+ void _testZlibLimit(u32 size, u32 limit);
};
static TestCompression g_test_instance;
@@ -46,6 +48,7 @@ void TestCompression::runTests(IGameDef *gamedef)
TEST(testRLECompression);
TEST(testZlibCompression);
TEST(testZlibLargeData);
+ TEST(testZlibLimit);
}
////////////////////////////////////////////////////////////////////////////////
@@ -170,3 +173,63 @@ void TestCompression::testZlibLargeData()
i, str_decompressed[i], i, data_in[i]);
}
}
+
+void TestCompression::testZlibLimit()
+{
+ // edge cases
+ _testZlibLimit(1024, 1023);
+ _testZlibLimit(1024, 1024);
+ _testZlibLimit(1024, 1025);
+
+ // test around buffer borders
+ u32 bufsize = 16384; // as in implementation
+ for (int s = -1; s <= 1; s++)
+ {
+ for (int l = -1; l <= 1; l++)
+ {
+ _testZlibLimit(bufsize + s, bufsize + l);
+ }
+ }
+ // span multiple buffers
+ _testZlibLimit(35000, 22000);
+ _testZlibLimit(22000, 35000);
+}
+
+void TestCompression::_testZlibLimit(u32 size, u32 limit)
+{
+ infostream << "Test: Testing zlib wrappers with a decompression "
+ "memory limit of " << limit << std::endl;
+
+ infostream << "Test: Input size of compressZlib for limit is "
+ << size << std::endl;
+
+ // how much data we expect to get
+ u32 expected = size < limit ? size : limit;
+
+ // create recognizable data
+ std::string data_in;
+ data_in.resize(size);
+ for (u32 i = 0; i < size; i++)
+ data_in[i] = (u8)(i % 256);
+
+ std::ostringstream os_compressed(std::ios::binary);
+ compressZlib(data_in, os_compressed);
+ infostream << "Test: Output size of compressZlib for limit is "
+ << os_compressed.str().size()<<std::endl;
+
+ std::istringstream is_compressed(os_compressed.str(), std::ios::binary);
+ std::ostringstream os_decompressed(std::ios::binary);
+ decompressZlib(is_compressed, os_decompressed, limit);
+ infostream << "Test: Output size of decompressZlib with limit is "
+ << os_decompressed.str().size() << std::endl;
+
+ std::string str_decompressed = os_decompressed.str();
+ UASSERTEQ(size_t, str_decompressed.size(), expected);
+
+ for (u32 i = 0; i < size && i < str_decompressed.size(); i++) {
+ UTEST(str_decompressed[i] == data_in[i],
+ "index out[%i]=%i differs from in[%i]=%i",
+ i, str_decompressed[i], i, data_in[i]);
+ }
+}
+