Introduce (private) ZLibFilter to dart:io.

runtime/bin/filter.cc

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include "bin/filter.h"
+#include "bin/dartutils.h"
+
+#include "include/dart_api.h"
+
+const int kZlibFlagMemUsage = 8;
+const int kZLibFlagWindowBits = 15;
+const int kZLibFlagUseGZipHeader = 16;
+const int kZLibFlagAcceptAnyHeader = 32;
+
+const intptr_t kFilterBufferLength = 64 * KB;
+
+static const int kFilterPointerNativeField = 0;
+
+void DeleteBuffer(void* buffer) {
+  delete[] reinterpret_cast<uint8_t*>(buffer);
+}
+
+Filter* GetFilter(Dart_Handle filter_obj) {
+  Filter* filter;
+  if (Dart_IsError(Filter::GetFilterPointerNativeField(filter_obj, &filter))
+      || filter == NULL) {
+    Dart_ThrowException(DartUtils::NewInternalError("Failed to get filter"));
+  }
+  return filter;
+}
+
+void EndFilter(Dart_Handle filter_obj, Filter* filter) {
+  Filter::SetFilterPointerNativeField(filter_obj, NULL);
+  delete filter;
+}
+
+void FUNCTION_NAME(Filter_CreateZLibInflate)(Dart_NativeArguments args) {
+  Dart_EnterScope();
+  Dart_Handle filter_obj = Dart_GetNativeArgument(args, 0);
+  Filter* filter = new ZLibInflateFilter();
+  if (!filter->Init() ||
+      Dart_IsError(Filter::SetFilterPointerNativeField(filter_obj, filter))) {
+    delete filter;
+    Dart_ThrowException(DartUtils::NewInternalError(
+        "Failed to create ZLibInflateFilter"));
+  }
+  Dart_ExitScope();
+}
+
+void FUNCTION_NAME(Filter_CreateGZipDeflate)(Dart_NativeArguments args) {
+  Dart_EnterScope();
+  Dart_Handle filter_obj = Dart_GetNativeArgument(args, 0);
+  Filter* filter = new ZLibDeflateFilter(true);
+  if (!filter->Init() ||
+      Dart_IsError(Filter::SetFilterPointerNativeField(filter_obj, filter))) {
+    delete filter;
+    Dart_ThrowException(DartUtils::NewInternalError(
+        "Failed to create GZipDeflateFilter"));
+  }
+  Dart_ExitScope();
+}
+
+void FUNCTION_NAME(Filter_Process)(Dart_NativeArguments args) {
+  Dart_EnterScope();
+  Dart_Handle filter_obj = Dart_GetNativeArgument(args, 0);
+  Filter* filter = GetFilter(filter_obj);
+  Dart_Handle data_obj = Dart_GetNativeArgument(args, 1);
+  intptr_t length;
+  if (Dart_IsError(Dart_ListLength(data_obj, &length))) {
+    Dart_ThrowException(DartUtils::NewInternalError(
+        "Failed to get data length"));
+  }
+  uint8_t* data = new uint8_t[length];
+  if (Dart_IsError(Dart_ListGetAsBytes(data_obj, 0, data, length))) {
+    DeleteBuffer(data);
+    Dart_ThrowException(DartUtils::NewInternalError(
+        "Failed to get data bytes"));
+  }
+  if (!filter->Process(data, length)) {
+    DeleteBuffer(data);
+    Dart_ThrowException(DartUtils::NewInternalError(
+        "Call to Process while still processing data"));
+  }
+  Dart_ExitScope();
+}
+
+
+void FUNCTION_NAME(Filter_Processed)(Dart_NativeArguments args) {
+  Dart_EnterScope();
+  Dart_Handle filter_obj = Dart_GetNativeArgument(args, 0);
+  Filter* filter = GetFilter(filter_obj);
+  Dart_Handle flush_obj = Dart_GetNativeArgument(args, 1);
+  bool flush;
+  if (Dart_IsError(Dart_BooleanValue(flush_obj, &flush))) {
+    Dart_ThrowException(DartUtils::NewInternalError(
+        "Failed to get 'flush' parameter"));
+  }
+  uint8_t* buffer = new uint8_t[kFilterBufferLength];
+  intptr_t read = filter->Processed(buffer, kFilterBufferLength, flush);
+  if (read < 0) {
+    // Error, end filter.
+    EndFilter(filter_obj, filter);
+    DeleteBuffer(buffer);
+    Dart_ThrowException(DartUtils::NewInternalError(
+        "Filter error, bad data"));
+  } else if (read == 0) {
+    DeleteBuffer(buffer);
+    Dart_SetReturnValue(args, Dart_Null());
+  } else {
+    Dart_Handle result = Dart_NewExternalByteArray(buffer,
+                                                   read,
+                                                   buffer,
+                                                   DeleteBuffer);
+    Dart_SetReturnValue(args, result);
+  }
+  Dart_ExitScope();
+}
+
+
+void FUNCTION_NAME(Filter_End)(Dart_NativeArguments args) {
+  Dart_EnterScope();
+  Dart_Handle filter_obj = Dart_GetNativeArgument(args, 0);
+  Filter* filter = GetFilter(filter_obj);
+  EndFilter(filter_obj, filter);
+  Dart_ExitScope();
+}
+
+
+Dart_Handle Filter::SetFilterPointerNativeField(Dart_Handle filter,
+                                                Filter* filter_pointer) {
+  return Dart_SetNativeInstanceField(filter,
+                                     kFilterPointerNativeField,
+                                     (intptr_t)filter_pointer);
+}
+
+
+Dart_Handle Filter::GetFilterPointerNativeField(Dart_Handle filter,
+                                                Filter** filter_pointer) {
+  return Dart_GetNativeInstanceField(
+      filter,
+      kFilterPointerNativeField,
+      reinterpret_cast<intptr_t*>(filter_pointer));
+}
+
+
+ZLibDeflateFilter::~ZLibDeflateFilter() {
+  delete[] current_buffer;
+  deflateEnd(&stream);
+}
+
+
+bool ZLibDeflateFilter::Init() {
+  stream.zalloc = Z_NULL;
+  stream.zfree = Z_NULL;
+  stream.opaque = Z_NULL;
+  return deflateInit2(&stream,
+                      level,
+                      Z_DEFLATED,
+                      kZLibFlagWindowBits | (gZip ? kZLibFlagUseGZipHeader : 0),
+                      kZlibFlagMemUsage,
+                      Z_DEFAULT_STRATEGY) == Z_OK;
+}
+
+
+bool ZLibDeflateFilter::Process(uint8_t* data, intptr_t length) {
+  if (current_buffer != NULL) return false;
+  stream.avail_in = length;
+  stream.next_in = current_buffer = data;
+  return true;
+}
+
+intptr_t ZLibDeflateFilter::Processed(uint8_t* buffer,
+                                      intptr_t length,
+                                      bool flush) {
+  stream.avail_out = length;
+  stream.next_out = buffer;
+  switch (deflate(&stream, flush ? Z_SYNC_FLUSH : Z_NO_FLUSH)) {
+    case Z_OK:
+      // We processed data, should be called again.
+      return length - stream.avail_out;
+
+    case Z_STREAM_END:
+    case Z_BUF_ERROR:
+      // We processed all available input data.
+      delete[] current_buffer;
+      current_buffer = NULL;
+      return 0;
+
+    default:
+    case Z_STREAM_ERROR:
+      // An error occoured.
+      delete[] current_buffer;
+      current_buffer = NULL;
+      return -1;
+  }
+}
+
+
+ZLibInflateFilter::~ZLibInflateFilter() {
+  delete[] current_buffer;
+  inflateEnd(&stream);
+}
+
+
+bool ZLibInflateFilter::Init() {
+  stream.zalloc = Z_NULL;
+  stream.zfree = Z_NULL;
+  stream.opaque = Z_NULL;
+  return inflateInit2(&stream,
+                      kZLibFlagWindowBits | kZLibFlagAcceptAnyHeader) == Z_OK;
+}
+
+
+bool ZLibInflateFilter::Process(uint8_t* data, intptr_t length) {
+  if (current_buffer != NULL) return false;
+  stream.avail_in = length;
+  stream.next_in = current_buffer = data;
+  return true;
+}
+
+
+intptr_t ZLibInflateFilter::Processed(uint8_t* buffer,
+                                      intptr_t length,
+                                      bool flush) {
+  stream.avail_out = length;
+  stream.next_out = buffer;
+  switch (inflate(&stream, flush ? Z_SYNC_FLUSH : Z_NO_FLUSH)) {
+    case Z_OK:
+      // We processed data, should be called again.
+      return length - stream.avail_out;
+
+    case Z_STREAM_END:
+    case Z_BUF_ERROR:
+      // We processed all available input data.
+      delete[] current_buffer;
+      current_buffer = NULL;
+      return 0;
+
+    default:
+    case Z_MEM_ERROR:
+    case Z_NEED_DICT:
+    case Z_DATA_ERROR:
+    case Z_STREAM_ERROR:
+      // An error occoured.
+      delete[] current_buffer;
+      current_buffer = NULL;
+      return -1;
+  }
+}
+