Move ICU headers from public/{common,i18n} to source/{common,i18n}

public/common/unicode/bytestream.h

-// Copyright (C) 2009-2010, International Business Machines
-// Corporation and others. All Rights Reserved.
-//
-// Copyright 2007 Google Inc. All Rights Reserved.
-// Author: sanjay@google.com (Sanjay Ghemawat)
-//
-// Abstract interface that consumes a sequence of bytes (ByteSink).
-//
-// Used so that we can write a single piece of code that can operate
-// on a variety of output string types.
-//
-// Various implementations of this interface are provided:
-//   ByteSink:
-//      CheckedArrayByteSink    Write to a flat array, with bounds checking
-//      StringByteSink          Write to an STL string
-
-// This code is a contribution of Google code, and the style used here is
-// a compromise between the original Google code and the ICU coding guidelines.
-// For example, data types are ICU-ified (size_t,int->int32_t),
-// and API comments doxygen-ified, but function names and behavior are
-// as in the original, if possible.
-// Assertion-style error handling, not available in ICU, was changed to
-// parameter "pinning" similar to UnicodeString.
-//
-// In addition, this is only a partial port of the original Google code,
-// limited to what was needed so far. The (nearly) complete original code
-// is in the ICU svn repository at icuhtml/trunk/design/strings/contrib
-// (see ICU ticket 6765, r25517).
-
-#ifndef __BYTESTREAM_H__
-#define __BYTESTREAM_H__
-
-/**
- * \file
- * \brief C++ API: Interface for writing bytes, and implementation classes.
- */
-
-#include "unicode/utypes.h"
-#include "unicode/uobject.h"
-#include "unicode/std_string.h"
-
-U_NAMESPACE_BEGIN
-
-/**
- * A ByteSink can be filled with bytes.
- * @stable ICU 4.2
- */
-class U_COMMON_API ByteSink : public UMemory {
-public:
-  /**
-   * Default constructor.
-   * @stable ICU 4.2
-   */
-  ByteSink() { }
-  /**
-   * Virtual destructor.
-   * @stable ICU 4.2
-   */
-  virtual ~ByteSink() { }
-
-  /**
-   * Append "bytes[0,n-1]" to this.
-   * @param bytes the pointer to the bytes
-   * @param n the number of bytes; must be non-negative
-   * @stable ICU 4.2
-   */
-  virtual void Append(const char* bytes, int32_t n) = 0;
-
-  /**
-   * Returns a writable buffer for appending and writes the buffer's capacity to
-   * *result_capacity. Guarantees *result_capacity>=min_capacity.
-   * May return a pointer to the caller-owned scratch buffer which must have
-   * scratch_capacity>=min_capacity.
-   * The returned buffer is only valid until the next operation
-   * on this ByteSink.
-   *
-   * After writing at most *result_capacity bytes, call Append() with the
-   * pointer returned from this function and the number of bytes written.
-   * Many Append() implementations will avoid copying bytes if this function
-   * returned an internal buffer.
-   *
-   * Partial usage example:
-   *  int32_t capacity;
-   *  char* buffer = sink->GetAppendBuffer(..., &capacity);
-   *  ... Write n bytes into buffer, with n <= capacity.
-   *  sink->Append(buffer, n);
-   * In many implementations, that call to Append will avoid copying bytes.
-   *
-   * If the ByteSink allocates or reallocates an internal buffer, it should use
-   * the desired_capacity_hint if appropriate.
-   * If a caller cannot provide a reasonable guess at the desired capacity,
-   * it should pass desired_capacity_hint=0.
-   *
-   * If a non-scratch buffer is returned, the caller may only pass
-   * a prefix to it to Append().
-   * That is, it is not correct to pass an interior pointer to Append().
-   *
-   * The default implementation always returns the scratch buffer.
-   *
-   * @param min_capacity required minimum capacity of the returned buffer;
-   *                     must be non-negative
-   * @param desired_capacity_hint desired capacity of the returned buffer;
-   *                              must be non-negative
-   * @param scratch default caller-owned buffer
-   * @param scratch_capacity capacity of the scratch buffer
-   * @param result_capacity pointer to an integer which will be set to the
-   *                        capacity of the returned buffer
-   * @return a buffer with *result_capacity>=min_capacity
-   * @stable ICU 4.2
-   */
-  virtual char* GetAppendBuffer(int32_t min_capacity,
-                                int32_t desired_capacity_hint,
-                                char* scratch, int32_t scratch_capacity,
-                                int32_t* result_capacity);
-
-  /**
-   * Flush internal buffers.
-   * Some byte sinks use internal buffers or provide buffering
-   * and require calling Flush() at the end of the stream.
-   * The ByteSink should be ready for further Append() calls after Flush().
-   * The default implementation of Flush() does nothing.
-   * @stable ICU 4.2
-   */
-  virtual void Flush();
-
-private:
-  ByteSink(const ByteSink &); // copy constructor not implemented
-  ByteSink &operator=(const ByteSink &); // assignment operator not implemented
-};
-
-// -------------------------------------------------------------
-// Some standard implementations
-
-/** 
- * Implementation of ByteSink that writes to a flat byte array,
- * with bounds-checking:
- * This sink will not write more than capacity bytes to outbuf.
- * If more than capacity bytes are Append()ed, then excess bytes are ignored,
- * and Overflowed() will return true.
- * Overflow does not cause a runtime error.
- * @stable ICU 4.2
- */
-class U_COMMON_API CheckedArrayByteSink : public ByteSink {
-public:
-  /**
-   * Constructs a ByteSink that will write to outbuf[0..capacity-1].
-   * @param outbuf buffer to write to
-   * @param capacity size of the buffer
-   * @stable ICU 4.2
-   */
-  CheckedArrayByteSink(char* outbuf, int32_t capacity);
-  /**
-   * Returns the sink to its original state, without modifying the buffer.
-   * Useful for reusing both the buffer and the sink for multiple streams.
-   * Resets the state to NumberOfBytesWritten()=NumberOfBytesAppended()=0
-   * and Overflowed()=FALSE.
-   * @return *this
-   * @draft ICU 4.6
-   */
-  virtual CheckedArrayByteSink& Reset();
-  /**
-   * Append "bytes[0,n-1]" to this.
-   * @param bytes the pointer to the bytes
-   * @param n the number of bytes; must be non-negative
-   * @stable ICU 4.2
-   */
-  virtual void Append(const char* bytes, int32_t n);
-  /**
-   * Returns a writable buffer for appending and writes the buffer's capacity to
-   * *result_capacity. For details see the base class documentation.
-   * @param min_capacity required minimum capacity of the returned buffer;
-   *                     must be non-negative
-   * @param desired_capacity_hint desired capacity of the returned buffer;
-   *                              must be non-negative
-   * @param scratch default caller-owned buffer
-   * @param scratch_capacity capacity of the scratch buffer
-   * @param result_capacity pointer to an integer which will be set to the
-   *                        capacity of the returned buffer
-   * @return a buffer with *result_capacity>=min_capacity
-   * @stable ICU 4.2
-   */
-  virtual char* GetAppendBuffer(int32_t min_capacity,
-                                int32_t desired_capacity_hint,
-                                char* scratch, int32_t scratch_capacity,
-                                int32_t* result_capacity);
-  /**
-   * Returns the number of bytes actually written to the sink.
-   * @return number of bytes written to the buffer
-   * @stable ICU 4.2
-   */
-  int32_t NumberOfBytesWritten() const { return size_; }
-  /**
-   * Returns true if any bytes were discarded, i.e., if there was an
-   * attempt to write more than 'capacity' bytes.
-   * @return TRUE if more than 'capacity' bytes were Append()ed
-   * @stable ICU 4.2
-   */
-  UBool Overflowed() const { return overflowed_; }
-  /**
-   * Returns the number of bytes appended to the sink.
-   * If Overflowed() then NumberOfBytesAppended()>NumberOfBytesWritten()
-   * else they return the same number.
-   * @return number of bytes written to the buffer
-   * @draft ICU 4.6
-   */
-  int32_t NumberOfBytesAppended() const { return appended_; }
-private:
-  char* outbuf_;
-  const int32_t capacity_;
-  int32_t size_;
-  int32_t appended_;
-  UBool overflowed_;
-  CheckedArrayByteSink(); ///< default constructor not implemented 
-  CheckedArrayByteSink(const CheckedArrayByteSink &); ///< copy constructor not implemented
-  CheckedArrayByteSink &operator=(const CheckedArrayByteSink &); ///< assignment operator not implemented
-};
-
-#if U_HAVE_STD_STRING
-
-/** 
- * Implementation of ByteSink that writes to a "string".
- * The StringClass is usually instantiated with a std::string.
- * @stable ICU 4.2
- */
-template<typename StringClass>
-class StringByteSink : public ByteSink {
- public:
-  /**
-   * Constructs a ByteSink that will append bytes to the dest string.
-   * @param dest pointer to string object to append to
-   * @stable ICU 4.2
-   */
-  StringByteSink(StringClass* dest) : dest_(dest) { }
-  /**
-   * Append "bytes[0,n-1]" to this.
-   * @param data the pointer to the bytes
-   * @param n the number of bytes; must be non-negative
-   * @stable ICU 4.2
-   */
-  virtual void Append(const char* data, int32_t n) { dest_->append(data, n); }
- private:
-  StringClass* dest_;
-  StringByteSink(); ///< default constructor not implemented 
-  StringByteSink(const StringByteSink &); ///< copy constructor not implemented
-  StringByteSink &operator=(const StringByteSink &); ///< assignment operator not implemented
-};
-
-#endif
-
-U_NAMESPACE_END
-
-#endif  // __BYTESTREAM_H__