ICU 62.1 62.1
bytestream.h
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1// © 2016 and later: Unicode, Inc. and others.
2// License & terms of use: http://www.unicode.org/copyright.html
3// Copyright (C) 2009-2012, International Business Machines
4// Corporation and others. All Rights Reserved.
5//
6// Copyright 2007 Google Inc. All Rights Reserved.
7// Author: sanjay@google.com (Sanjay Ghemawat)
8//
9// Abstract interface that consumes a sequence of bytes (ByteSink).
10//
11// Used so that we can write a single piece of code that can operate
12// on a variety of output string types.
13//
14// Various implementations of this interface are provided:
15// ByteSink:
16// CheckedArrayByteSink Write to a flat array, with bounds checking
17// StringByteSink Write to an STL string
18
19// This code is a contribution of Google code, and the style used here is
20// a compromise between the original Google code and the ICU coding guidelines.
21// For example, data types are ICU-ified (size_t,int->int32_t),
22// and API comments doxygen-ified, but function names and behavior are
23// as in the original, if possible.
24// Assertion-style error handling, not available in ICU, was changed to
25// parameter "pinning" similar to UnicodeString.
26//
27// In addition, this is only a partial port of the original Google code,
28// limited to what was needed so far. The (nearly) complete original code
29// is in the ICU svn repository at icuhtml/trunk/design/strings/contrib
30// (see ICU ticket 6765, r25517).
31
32#ifndef __BYTESTREAM_H__
33#define __BYTESTREAM_H__
34
40#include "unicode/utypes.h"
41#include "unicode/uobject.h"
42#include "unicode/std_string.h"
43
45
51public:
61 virtual ~ByteSink();
62
69 virtual void Append(const char* bytes, int32_t n) = 0;
70
113 virtual char* GetAppendBuffer(int32_t min_capacity,
114 int32_t desired_capacity_hint,
115 char* scratch, int32_t scratch_capacity,
116 int32_t* result_capacity);
117
126 virtual void Flush();
127
128private:
129 ByteSink(const ByteSink &) = delete;
130 ByteSink &operator=(const ByteSink &) = delete;
131};
132
133// -------------------------------------------------------------
134// Some standard implementations
135
146public:
153 CheckedArrayByteSink(char* outbuf, int32_t capacity);
174 virtual void Append(const char* bytes, int32_t n);
189 virtual char* GetAppendBuffer(int32_t min_capacity,
190 int32_t desired_capacity_hint,
191 char* scratch, int32_t scratch_capacity,
192 int32_t* result_capacity);
198 int32_t NumberOfBytesWritten() const { return size_; }
205 UBool Overflowed() const { return overflowed_; }
213 int32_t NumberOfBytesAppended() const { return appended_; }
214private:
215 char* outbuf_;
216 const int32_t capacity_;
217 int32_t size_;
218 int32_t appended_;
219 UBool overflowed_;
220
221 CheckedArrayByteSink() = delete;
223 CheckedArrayByteSink &operator=(const CheckedArrayByteSink &) = delete;
224};
225
231template<typename StringClass>
232class StringByteSink : public ByteSink {
233 public:
239 StringByteSink(StringClass* dest) : dest_(dest) { }
240#ifndef U_HIDE_DRAFT_API
248 StringByteSink(StringClass* dest, int32_t initialAppendCapacity) : dest_(dest) {
249 if (initialAppendCapacity > 0 &&
250 (uint32_t)initialAppendCapacity > (dest->capacity() - dest->length())) {
251 dest->reserve(dest->length() + initialAppendCapacity);
252 }
253 }
254#endif // U_HIDE_DRAFT_API
261 virtual void Append(const char* data, int32_t n) { dest_->append(data, n); }
262 private:
263 StringClass* dest_;
264
265 StringByteSink() = delete;
266 StringByteSink(const StringByteSink &) = delete;
267 StringByteSink &operator=(const StringByteSink &) = delete;
268};
269
271
272#endif // __BYTESTREAM_H__
A ByteSink can be filled with bytes.
Definition bytestream.h:50
virtual char * GetAppendBuffer(int32_t min_capacity, int32_t desired_capacity_hint, char *scratch, int32_t scratch_capacity, int32_t *result_capacity)
Returns a writable buffer for appending and writes the buffer's capacity to *result_capacity.
virtual void Append(const char *bytes, int32_t n)=0
Append "bytes[0,n-1]" to this.
ByteSink()
Default constructor.
Definition bytestream.h:56
virtual void Flush()
Flush internal buffers.
virtual ~ByteSink()
Virtual destructor.
Implementation of ByteSink that writes to a flat byte array, with bounds-checking: This sink will not...
Definition bytestream.h:145
int32_t NumberOfBytesWritten() const
Returns the number of bytes actually written to the sink.
Definition bytestream.h:198
CheckedArrayByteSink(char *outbuf, int32_t capacity)
Constructs a ByteSink that will write to outbuf[0..capacity-1].
virtual ~CheckedArrayByteSink()
Destructor.
virtual CheckedArrayByteSink & Reset()
Returns the sink to its original state, without modifying the buffer.
virtual char * GetAppendBuffer(int32_t min_capacity, int32_t desired_capacity_hint, char *scratch, int32_t scratch_capacity, int32_t *result_capacity)
Returns a writable buffer for appending and writes the buffer's capacity to *result_capacity.
int32_t NumberOfBytesAppended() const
Returns the number of bytes appended to the sink.
Definition bytestream.h:213
virtual void Append(const char *bytes, int32_t n)
Append "bytes[0,n-1]" to this.
UBool Overflowed() const
Returns true if any bytes were discarded, i.e., if there was an attempt to write more than 'capacity'...
Definition bytestream.h:205
Implementation of ByteSink that writes to a "string".
Definition bytestream.h:232
StringByteSink(StringClass *dest, int32_t initialAppendCapacity)
Constructs a ByteSink that reserves append capacity and will append bytes to the dest string.
Definition bytestream.h:248
StringByteSink(StringClass *dest)
Constructs a ByteSink that will append bytes to the dest string.
Definition bytestream.h:239
UMemory is the common ICU base class.
Definition uobject.h:112
C++ API: Central ICU header for including the C++ standard <string> header and for related definition...
int8_t UBool
The ICU boolean type.
Definition umachine.h:236
C++ API: Common ICU base class UObject.
Basic definitions for ICU, for both C and C++ APIs.
#define U_COMMON_API
Set to export library symbols from inside the common library, and to import them from outside.
Definition utypes.h:359
#define U_NAMESPACE_END
This is used to end a declaration of a public ICU C++ API.
Definition uversion.h:138
#define U_NAMESPACE_BEGIN
This is used to begin a declaration of a public ICU C++ API.
Definition uversion.h:137