Introduce ZLibInflater and ZLibDeflater to dart:io.

runtime/bin/filter.cc

+// Copyright (c) 2013, 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/dartutils.h"
+#include "bin/filter.h"
+#include "bin/io_buffer.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;
+
+Filter* GetFilter(Dart_Handle filter_obj) {
+  Filter* filter;
+  Dart_Handle result = Filter::GetFilterPointerNativeField(filter_obj, &filter);
+  if (Dart_IsError(result)) {
+    Dart_PropagateError(result);
+  }
+  if (filter == NULL) {
+    Dart_ThrowException(DartUtils::NewInternalError("Filter destroyed"));
+  }
+  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 == NULL || !filter->Init()) {
+    delete filter;
+    Dart_ThrowException(DartUtils::NewInternalError(
+        "Failed to create ZLibInflateFilter"));
+  }
+  Dart_Handle result = Filter::SetFilterPointerNativeField(filter_obj, filter);
+  if (Dart_IsError(result)) {
+    delete filter;
+    Dart_PropagateError(result);
+  }
+  Dart_ExitScope();
+}
+
+void FUNCTION_NAME(Filter_CreateZLibDeflate)(Dart_NativeArguments args) {
+  Dart_EnterScope();
+  Dart_Handle filter_obj = Dart_GetNativeArgument(args, 0);
+  Dart_Handle gzip_obj = Dart_GetNativeArgument(args, 1);
+  Dart_Handle level_obj = Dart_GetNativeArgument(args, 2);
+  bool gzip;
+  if (Dart_IsError(Dart_BooleanValue(gzip_obj, &gzip))) {
+    Dart_ThrowException(DartUtils::NewInternalError(
+        "Failed to get 'gzip' parameter"));
+  }
+  int64_t level;
+  if (Dart_IsError(Dart_IntegerToInt64(level_obj, &level))) {
+    Dart_ThrowException(DartUtils::NewInternalError(
+        "Failed to get 'level' parameter"));
+  }
+  Filter* filter = new ZLibDeflateFilter(gzip, level);
+  if (filter == NULL || !filter->Init()) {
+    delete filter;
+    Dart_ThrowException(DartUtils::NewInternalError(
+        "Failed to create ZLibDeflateFilter"));
+  }
+  Dart_Handle result = Filter::SetFilterPointerNativeField(filter_obj, filter);
+  if (Dart_IsError(result)) {
+    delete filter;
+    Dart_PropagateError(result);
+  }
+  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;
+  Dart_TypedData_Type type;
+  uint8_t* buffer = NULL;
+  Dart_Handle result = Dart_TypedDataAcquireData(
+      data_obj, &type, reinterpret_cast<void**>(&buffer), &length);
+  if (!Dart_IsError(result)) {
+    uint8_t* zlib_buffer = new uint8_t[length];
+    if (zlib_buffer == NULL) {
+      Dart_TypedDataReleaseData(data_obj);
+      Dart_ThrowException(DartUtils::NewInternalError(
+          "Failed to allocate buffer for zlib"));
+    }
+    memmove(zlib_buffer, buffer, length);
+    Dart_TypedDataReleaseData(data_obj);
+    buffer = zlib_buffer;
+  } else {
+    if (Dart_IsError(Dart_ListLength(data_obj, &length))) {
+      Dart_ThrowException(DartUtils::NewInternalError(
+          "Failed to get list length"));
+    }
+    buffer = new uint8_t[length];
+    if (Dart_IsError(Dart_ListGetAsBytes(data_obj, 0, buffer, length))) {
+      delete[] buffer;
+      Dart_ThrowException(DartUtils::NewInternalError(
+          "Failed to get list bytes"));
+    }
+  }
+  // Process will take ownership of buffer, if successful.
+  if (!filter->Process(buffer, length)) {
+    delete[] buffer;
+    EndFilter(filter_obj, filter);
+    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[kFilterBufferLength];
+  intptr_t read = filter->Processed(buffer, kFilterBufferLength, flush);
+  if (read < 0) {
+    // Error, end filter.
+    EndFilter(filter_obj, filter);
+    Dart_ThrowException(DartUtils::NewInternalError(
+        "Filter error, bad data"));
+  } else if (read == 0) {
+    Dart_SetReturnValue(args, Dart_Null());
+  } else {
+    uint8_t* io_buffer;
+    Dart_Handle result = IOBuffer::Allocate(read, &io_buffer);
+    memmove(io_buffer, buffer, read);
+    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;
+  if (initialized) deflateEnd(&stream);
+}
+
+
+bool ZLibDeflateFilter::Init() {
+  stream.zalloc = Z_NULL;
+  stream.zfree = Z_NULL;
+  stream.opaque = Z_NULL;
+  int result = deflateInit2(
+      &stream,
+      level,
+      Z_DEFLATED,
+      kZLibFlagWindowBits | (gZip ? kZLibFlagUseGZipHeader : 0),
+      kZlibFlagMemUsage,
+      Z_DEFAULT_STRATEGY);
+  if (result == Z_OK) {
+    initialized = true;
+    return true;
+  }
+  return false;
+}
+
+
+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: {
+      intptr_t processed = length - stream.avail_out;
+      if (processed == 0) {
+        delete[] current_buffer;
+        current_buffer = NULL;
+        return 0;
+      } else {
+        // We processed data, should be called again.
+        return processed;
+      }
+    }
+
+    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;
+  if (initialized) inflateEnd(&stream);
+}
+
+
+bool ZLibInflateFilter::Init() {
+  stream.zalloc = Z_NULL;
+  stream.zfree = Z_NULL;
+  stream.opaque = Z_NULL;
+  int result = inflateInit2(&stream,
+                            kZLibFlagWindowBits | kZLibFlagAcceptAnyHeader);
+  if (result == Z_OK) {
+    initialized = true;
+    return true;
+  }
+  return false;
+}
+
+
+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: {
+      intptr_t processed = length - stream.avail_out;
+      if (processed == 0) {
+        delete[] current_buffer;
+        current_buffer = NULL;
+        return 0;
+      } else {
+        // We processed data, should be called again.
+        return processed;
+      }
+    }
+
+    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;
+  }
+}
+