Index: net/base/io_buffer.h |
diff --git a/net/base/io_buffer.h b/net/base/io_buffer.h |
deleted file mode 100644 |
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--- a/net/base/io_buffer.h |
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@@ -1,245 +0,0 @@ |
-// Copyright (c) 2012 The Chromium Authors. All rights reserved. |
-// Use of this source code is governed by a BSD-style license that can be |
-// found in the LICENSE file. |
- |
-#ifndef NET_BASE_IO_BUFFER_H_ |
-#define NET_BASE_IO_BUFFER_H_ |
- |
-#include <string> |
- |
-#include "base/memory/ref_counted.h" |
-#include "base/memory/scoped_ptr.h" |
-#include "base/pickle.h" |
-#include "net/base/net_export.h" |
- |
-namespace net { |
- |
-// IOBuffers are reference counted data buffers used for easier asynchronous |
-// IO handling. |
-// |
-// They are often used as the destination buffers for Read() operations, or as |
-// the source buffers for Write() operations. |
-// |
-// IMPORTANT: Never re-use an IOBuffer after cancelling the IO operation that |
-// was using it, since this may lead to memory corruption! |
-// |
-// ----------------------- |
-// Ownership of IOBuffers: |
-// ----------------------- |
-// |
-// Although IOBuffers are RefCountedThreadSafe, they are not intended to be |
-// used as a shared buffer, nor should they be used simultaneously across |
-// threads. The fact that they are reference counted is an implementation |
-// detail for allowing them to outlive cancellation of asynchronous |
-// operations. |
-// |
-// Instead, think of the underlying |char*| buffer contained by the IOBuffer |
-// as having exactly one owner at a time. |
-// |
-// Whenever you call an asynchronous operation that takes an IOBuffer, |
-// ownership is implicitly transferred to the called function, until the |
-// operation has completed (at which point it transfers back to the caller). |
-// |
-// ==> The IOBuffer's data should NOT be manipulated, destroyed, or read |
-// until the operation has completed. |
-// |
-// ==> Cancellation does NOT count as completion. If an operation using |
-// an IOBuffer is cancelled, the caller should release their |
-// reference to this IOBuffer at the time of cancellation since |
-// they can no longer use it. |
-// |
-// For instance, if you were to call a Read() operation on some class which |
-// takes an IOBuffer, and then delete that class (which generally will |
-// trigger cancellation), the IOBuffer which had been passed to Read() should |
-// never be re-used. |
-// |
-// This usage contract is assumed by any API which takes an IOBuffer, even |
-// though it may not be explicitly mentioned in the function's comments. |
-// |
-// ----------------------- |
-// Motivation |
-// ----------------------- |
-// |
-// The motivation for transferring ownership during cancellation is |
-// to make it easier to work with un-cancellable operations. |
-// |
-// For instance, let's say under the hood your API called out to the |
-// operating system's synchronous ReadFile() function on a worker thread. |
-// When cancelling through our asynchronous interface, we have no way of |
-// actually aborting the in progress ReadFile(). We must let it keep running, |
-// and hence the buffer it was reading into must remain alive. Using |
-// reference counting we can add a reference to the IOBuffer and make sure |
-// it is not destroyed until after the synchronous operation has completed. |
-class NET_EXPORT IOBuffer : public base::RefCountedThreadSafe<IOBuffer> { |
- public: |
- IOBuffer(); |
- explicit IOBuffer(int buffer_size); |
- |
- char* data() { return data_; } |
- |
- protected: |
- friend class base::RefCountedThreadSafe<IOBuffer>; |
- |
- // Only allow derived classes to specify data_. |
- // In all other cases, we own data_, and must delete it at destruction time. |
- explicit IOBuffer(char* data); |
- |
- virtual ~IOBuffer(); |
- |
- char* data_; |
-}; |
- |
-// This version stores the size of the buffer so that the creator of the object |
-// doesn't have to keep track of that value. |
-// NOTE: This doesn't mean that we want to stop sending the size as an explicit |
-// argument to IO functions. Please keep using IOBuffer* for API declarations. |
-class NET_EXPORT IOBufferWithSize : public IOBuffer { |
- public: |
- explicit IOBufferWithSize(int size); |
- |
- int size() const { return size_; } |
- |
- protected: |
- // Purpose of this constructor is to give a subclass access to the base class |
- // constructor IOBuffer(char*) thus allowing subclass to use underlying |
- // memory it does not own. |
- IOBufferWithSize(char* data, int size); |
- ~IOBufferWithSize() override; |
- |
- int size_; |
-}; |
- |
-// This is a read only IOBuffer. The data is stored in a string and |
-// the IOBuffer interface does not provide a proper way to modify it. |
-class NET_EXPORT StringIOBuffer : public IOBuffer { |
- public: |
- explicit StringIOBuffer(const std::string& s); |
- explicit StringIOBuffer(scoped_ptr<std::string> s); |
- |
- int size() const { return static_cast<int>(string_data_.size()); } |
- |
- private: |
- ~StringIOBuffer() override; |
- |
- std::string string_data_; |
-}; |
- |
-// This version wraps an existing IOBuffer and provides convenient functions |
-// to progressively read all the data. |
-// |
-// DrainableIOBuffer is useful when you have an IOBuffer that contains data |
-// to be written progressively, and Write() function takes an IOBuffer rather |
-// than char*. DrainableIOBuffer can be used as follows: |
-// |
-// // payload is the IOBuffer containing the data to be written. |
-// buf = new DrainableIOBuffer(payload, payload_size); |
-// |
-// while (buf->BytesRemaining() > 0) { |
-// // Write() takes an IOBuffer. If it takes char*, we could |
-// // simply use the regular IOBuffer like payload->data() + offset. |
-// int bytes_written = Write(buf, buf->BytesRemaining()); |
-// buf->DidConsume(bytes_written); |
-// } |
-// |
-class NET_EXPORT DrainableIOBuffer : public IOBuffer { |
- public: |
- DrainableIOBuffer(IOBuffer* base, int size); |
- |
- // DidConsume() changes the |data_| pointer so that |data_| always points |
- // to the first unconsumed byte. |
- void DidConsume(int bytes); |
- |
- // Returns the number of unconsumed bytes. |
- int BytesRemaining() const; |
- |
- // Returns the number of consumed bytes. |
- int BytesConsumed() const; |
- |
- // Seeks to an arbitrary point in the buffer. The notion of bytes consumed |
- // and remaining are updated appropriately. |
- void SetOffset(int bytes); |
- |
- int size() const { return size_; } |
- |
- private: |
- ~DrainableIOBuffer() override; |
- |
- scoped_refptr<IOBuffer> base_; |
- int size_; |
- int used_; |
-}; |
- |
-// This version provides a resizable buffer and a changeable offset. |
-// |
-// GrowableIOBuffer is useful when you read data progressively without |
-// knowing the total size in advance. GrowableIOBuffer can be used as |
-// follows: |
-// |
-// buf = new GrowableIOBuffer; |
-// buf->SetCapacity(1024); // Initial capacity. |
-// |
-// while (!some_stream->IsEOF()) { |
-// // Double the capacity if the remaining capacity is empty. |
-// if (buf->RemainingCapacity() == 0) |
-// buf->SetCapacity(buf->capacity() * 2); |
-// int bytes_read = some_stream->Read(buf, buf->RemainingCapacity()); |
-// buf->set_offset(buf->offset() + bytes_read); |
-// } |
-// |
-class NET_EXPORT GrowableIOBuffer : public IOBuffer { |
- public: |
- GrowableIOBuffer(); |
- |
- // realloc memory to the specified capacity. |
- void SetCapacity(int capacity); |
- int capacity() { return capacity_; } |
- |
- // |offset| moves the |data_| pointer, allowing "seeking" in the data. |
- void set_offset(int offset); |
- int offset() { return offset_; } |
- |
- int RemainingCapacity(); |
- char* StartOfBuffer(); |
- |
- private: |
- ~GrowableIOBuffer() override; |
- |
- scoped_ptr<char, base::FreeDeleter> real_data_; |
- int capacity_; |
- int offset_; |
-}; |
- |
-// This versions allows a pickle to be used as the storage for a write-style |
-// operation, avoiding an extra data copy. |
-class NET_EXPORT PickledIOBuffer : public IOBuffer { |
- public: |
- PickledIOBuffer(); |
- |
- Pickle* pickle() { return &pickle_; } |
- |
- // Signals that we are done writing to the pickle and we can use it for a |
- // write-style IO operation. |
- void Done(); |
- |
- private: |
- ~PickledIOBuffer() override; |
- |
- Pickle pickle_; |
-}; |
- |
-// This class allows the creation of a temporary IOBuffer that doesn't really |
-// own the underlying buffer. Please use this class only as a last resort. |
-// A good example is the buffer for a synchronous operation, where we can be |
-// sure that nobody is keeping an extra reference to this object so the lifetime |
-// of the buffer can be completely managed by its intended owner. |
-class NET_EXPORT WrappedIOBuffer : public IOBuffer { |
- public: |
- explicit WrappedIOBuffer(const char* data); |
- |
- protected: |
- ~WrappedIOBuffer() override; |
-}; |
- |
-} // namespace net |
- |
-#endif // NET_BASE_IO_BUFFER_H_ |