Workaround for bug in zlib-ng; using zlib level 3 by default

dbms/src/IO/ZlibDeflatingWriteBuffer.cpp

@@ -5,6 +5,12 @@
 namespace DB
 {
 
+namespace ErrorCodes
+{
+    extern const int ZLIB_DEFLATE_FAILED;
+}
+
+
 ZlibDeflatingWriteBuffer::ZlibDeflatingWriteBuffer(
         std::unique_ptr<WriteBuffer> out_,
         CompressionMethod compression_method,
@@ -84,6 +90,21 @@ void ZlibDeflatingWriteBuffer::finish()
 
     next();
 
+    /// https://github.com/zlib-ng/zlib-ng/issues/494
+    do
+    {
+        out->nextIfAtEnd();
+        zstr.next_out = reinterpret_cast<unsigned char *>(out->position());
+        zstr.avail_out = out->buffer().end() - out->position();
+
+        int rc = deflate(&zstr, Z_FULL_FLUSH);
+        out->position() = out->buffer().end() - zstr.avail_out;
+
+        if (rc != Z_OK)
+            throw Exception(std::string("deflate failed: ") + zError(rc), ErrorCodes::ZLIB_DEFLATE_FAILED);
+    }
+    while (zstr.avail_out == 0);
+
     while (true)
     {
         out->nextIfAtEnd();

dbms/src/IO/ZlibDeflatingWriteBuffer.h

@@ -10,11 +10,6 @@
 namespace DB
 {
 
-namespace ErrorCodes
-{
-    extern const int ZLIB_DEFLATE_FAILED;
-}
-
 /// Performs compression using zlib library and writes compressed data to out_ WriteBuffer.
 class ZlibDeflatingWriteBuffer : public BufferWithOwnMemory<WriteBuffer>
 {

dbms/src/IO/tests/CMakeLists.txt

@@ -78,7 +78,4 @@ add_executable (parse_date_time_best_effort parse_date_time_best_effort.cpp)
 target_link_libraries (parse_date_time_best_effort PRIVATE clickhouse_common_io)
 
 add_executable (zlib_ng_bug zlib_ng_bug.cpp)
-target_link_libraries (zlib_ng_bug PRIVATE ${Poco_Foundation_LIBRARY})
-if(NOT USE_INTERNAL_POCO_LIBRARY)
-    target_include_directories(zlib_ng_bug SYSTEM BEFORE PRIVATE ${Poco_INCLUDE_DIRS})
-endif()
+target_link_libraries (zlib_ng_bug PRIVATE ${Poco_Foundation_LIBRARY} ${ZLIB_LIBRARY})

dbms/src/IO/tests/zlib_ng_bug.cpp

@@ -1,32 +1,50 @@
-#include <Poco/FileStream.h>
-#include <Poco/NullStream.h>
-#include <Poco/StreamCopier.h>
-#include <Poco/DeflatingStream.h>
+#include <unistd.h>
+#include <vector>
+#include <stdexcept>
+#include <zlib.h>
 
-/** This script reproduces the bug in zlib-ng library.
-  * Put the following content to "data.bin" file:
-abcdefghijklmn!@Aab#AAabcdefghijklmn$%
-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
-  * There are two lines. First line make sense. Second line contains padding to make file size large enough.
-  * Compile with
-  *  cmake -D SANITIZE=address
-  * and run:
+#pragma GCC diagnostic ignored "-Wold-style-cast"
 
-./zlib_ng_bug data2.bin
-=================================================================
-==204952==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6310000147ff at pc 0x000000596d7a bp 0x7ffd139edd50 sp 0x7ffd139edd48
-READ of size 1 at 0x6310000147ff thread T0
-  */
 
-int main(int argc, char ** argv)
+/// https://github.com/zlib-ng/zlib-ng/issues/494
+int main(int, char **)
 {
-    using namespace Poco;
+    std::vector<unsigned char> in(1048576);
+    std::vector<unsigned char> out(1048576);
 
-    std::string filename(argc >= 2 ? argv[1] : "data.bin");
-    FileInputStream istr(filename);
-    NullOutputStream ostr;
-    DeflatingOutputStream deflater(ostr, DeflatingStreamBuf::STREAM_GZIP);
-    StreamCopier::copyStream(istr, deflater);
+    ssize_t in_size = read(STDIN_FILENO, in.data(), 1048576);
+    if (in_size < 0)
+        throw std::runtime_error("Cannot read");
+    in.resize(in_size);
+
+    z_stream zstr{};
+    if (Z_OK != deflateInit2(&zstr, 1, Z_DEFLATED, 15 + 16, 8, Z_DEFAULT_STRATEGY))
+        throw std::runtime_error("Cannot deflateInit2");
+
+    zstr.next_in = in.data();
+    zstr.avail_in = in.size();
+    zstr.next_out = out.data();
+    zstr.avail_out = out.size();
+
+    while (zstr.avail_in > 0)
+        if (Z_OK != deflate(&zstr, Z_NO_FLUSH))
+            throw std::runtime_error("Cannot deflate");
+
+    while (true)
+    {
+        int rc = deflate(&zstr, Z_FINISH);
+
+        if (rc == Z_STREAM_END)
+            break;
+
+        if (rc != Z_OK)
+            throw std::runtime_error("Cannot finish deflate");
+    }
+
+    deflateEnd(&zstr);
+
+    if (ssize_t(zstr.total_out) != write(STDOUT_FILENO, out.data(), zstr.total_out))
+        throw std::runtime_error("Cannot write");
 
     return 0;
 }

dbms/src/Storages/StorageFile.cpp

@@ -291,7 +291,7 @@ public:
               * INSERT data; SELECT *; last SELECT returns only insert_data
               */
             storage.table_fd_was_used = true;
-            write_buf = wrapWriteBufferWithCompressionMethod(std::make_unique<WriteBufferFromFileDescriptor>(storage.table_fd), compression_method, 1);
+            write_buf = wrapWriteBufferWithCompressionMethod(std::make_unique<WriteBufferFromFileDescriptor>(storage.table_fd), compression_method, 3);
         }
         else
         {
@@ -299,7 +299,7 @@ public:
                 throw Exception("Table '" + storage.table_name + "' is in readonly mode because of globs in filepath", ErrorCodes::DATABASE_ACCESS_DENIED);
             write_buf = wrapWriteBufferWithCompressionMethod(
                 std::make_unique<WriteBufferFromFile>(storage.paths[0], DBMS_DEFAULT_BUFFER_SIZE, O_WRONLY | O_APPEND | O_CREAT),
-                compression_method, 1);
+                compression_method, 3);
         }
 
         writer = FormatFactory::instance().getOutput(storage.format_name, *write_buf, storage.getSampleBlock(), context);

dbms/src/Storages/StorageHDFS.cpp

@@ -112,7 +112,7 @@ public:
         const CompressionMethod compression_method)
         : sample_block(sample_block_)
     {
-        write_buf = wrapWriteBufferWithCompressionMethod(std::make_unique<WriteBufferFromHDFS>(uri), compression_method, 1);
+        write_buf = wrapWriteBufferWithCompressionMethod(std::make_unique<WriteBufferFromHDFS>(uri), compression_method, 3);
         writer = FormatFactory::instance().getOutput(format, *write_buf, sample_block, context);
     }
 

dbms/src/Storages/StorageS3.cpp

@@ -99,7 +99,7 @@ namespace
             : sample_block(sample_block_)
         {
             write_buf = wrapWriteBufferWithCompressionMethod(
-                std::make_unique<WriteBufferFromS3>(client, bucket, key, min_upload_part_size), compression_method, 1);
+                std::make_unique<WriteBufferFromS3>(client, bucket, key, min_upload_part_size), compression_method, 3);
             writer = FormatFactory::instance().getOutput(format, *write_buf, sample_block, context);
         }
 

dbms/src/Storages/StorageURL.cpp

@@ -120,7 +120,7 @@ namespace
         {
             write_buf = wrapWriteBufferWithCompressionMethod(
                 std::make_unique<WriteBufferFromHTTP>(uri, Poco::Net::HTTPRequest::HTTP_POST, timeouts),
-                compression_method, 1);
+                compression_method, 3);
             writer = FormatFactory::instance().getOutput(format, *write_buf, sample_block, context);
         }