1
// Copyright (c) 2017-2022 Cloudflare, Inc.
2
// Licensed under the Apache 2.0 license found in the LICENSE file or at:
3
//     https://opensource.org/licenses/Apache-2.0
4
 
5
#pragma once
6
 
7
#include <workerd/api/streams/transform.h>
8
#include <workerd/jsg/jsg.h>
9
 
10
#include <zlib.h>
11
 
12
namespace workerd::api {
13
 
14
// A custom allocator to be used by the zlib and brotli libraries.
15
// The allocator should not and can not safely hold a reference to the jsg::Lock
16
// instance. Therefore, we lookup the current jsg::Lock instance from the
17
// isolate pointer and use that to get the external memory adjustment.
18
class CompressionAllocator final {
19
 public:
20
  CompressionAllocator(kj::Arc<const jsg::ExternalMemoryTarget>&& externalMemoryTarget);
21
  void configure(z_stream* stream);
22
 
23
  static void* AllocForZlib(void* data, uInt items, uInt size);
24
  static void* AllocForBrotli(void* data, size_t size);
25
  static void FreeForZlib(void* data, void* pointer);
26
 
27
 private:
28
  struct Allocation {
29
    kj::Array<kj::byte> data;
30
    kj::Maybe<jsg::ExternalMemoryAdjustment> memoryAdjustment = kj::none;
31
  };
32
 
33
  kj::Arc<const jsg::ExternalMemoryTarget> externalMemoryTarget;
34
  kj::HashMap<void*, Allocation> allocations;
35
};
36
 
37
class CompressionStream: public TransformStream {
38
 public:
39
  using TransformStream::TransformStream;
40
 
41
  static jsg::Ref<CompressionStream> constructor(jsg::Lock& js, kj::String format);
42
 
43
  JSG_RESOURCE_TYPE(CompressionStream) {
44
    JSG_INHERIT(TransformStream);
45
 
46
    JSG_TS_OVERRIDE(extends TransformStream<ArrayBuffer | ArrayBufferView, Uint8Array> { constructor(format
47
                                 : "gzip" | "deflate" | "deflate-raw");
48
    });
49
  }
50
};
51
 
52
class DecompressionStream: public TransformStream {
53
 public:
54
  using TransformStream::TransformStream;
55
 
56
  static jsg::Ref<DecompressionStream> constructor(jsg::Lock& js, kj::String format);
57
 
58
  JSG_RESOURCE_TYPE(DecompressionStream) {
59
    JSG_INHERIT(TransformStream);
60
 
61
    JSG_TS_OVERRIDE(extends TransformStream<ArrayBuffer | ArrayBufferView, Uint8Array> { constructor(format
62
                                 : "gzip" | "deflate" | "deflate-raw");
63
    });
64
  }
65
};
66
 
67
}  // namespace workerd::api