ICU 74.2 74.2

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
42#if U_SHOW_CPLUSPLUS_API
43
44#include "unicode/uobject.h"
45#include "unicode/std_string.h"
46
47U_NAMESPACE_BEGIN
48
53 class U_COMMON_API ByteSink : public UMemory {
54 public:
59 ByteSink() { }
64 virtual ~ByteSink();
65
72 virtual void Append(const char* bytes, int32_t n) = 0;
73
85 inline void AppendU8(const char* bytes, int32_t n) {
86 Append(bytes, n);
87 }
88
89#if defined(__cpp_char8_t) || defined(U_IN_DOXYGEN)
101 inline void AppendU8(const char8_t* bytes, int32_t n) {
102 Append(reinterpret_cast<const char*>(bytes), n);
103 }
104#endif
105
148 virtual char* GetAppendBuffer(int32_t min_capacity,
149 int32_t desired_capacity_hint,
150 char* scratch, int32_t scratch_capacity,
151 int32_t* result_capacity);
152
161 virtual void Flush();
162
163 private:
164 ByteSink(const ByteSink &) = delete;
165 ByteSink &operator=(const ByteSink &) = delete;
166};
167
168// -------------------------------------------------------------
169// Some standard implementations
170
180 class U_COMMON_API CheckedArrayByteSink : public ByteSink {
181 public:
188 CheckedArrayByteSink(char* outbuf, int32_t capacity);
193 virtual ~CheckedArrayByteSink();
202 virtual CheckedArrayByteSink& Reset();
209 virtual void Append(const char* bytes, int32_t n) override;
224 virtual char* GetAppendBuffer(int32_t min_capacity,
225 int32_t desired_capacity_hint,
226 char* scratch, int32_t scratch_capacity,
227 int32_t* result_capacity) override;
233 int32_t NumberOfBytesWritten() const { return size_; }
240 UBool Overflowed() const { return overflowed_; }
248 int32_t NumberOfBytesAppended() const { return appended_; }
249 private:
250 char* outbuf_;
251 const int32_t capacity_;
252 int32_t size_;
253 int32_t appended_;
254 UBool overflowed_;
255
256 CheckedArrayByteSink() = delete;
257 CheckedArrayByteSink(const CheckedArrayByteSink &) = delete;
258 CheckedArrayByteSink &operator=(const CheckedArrayByteSink &) = delete;
259};
260
266 template<typename StringClass>
267 class StringByteSink : public ByteSink {
268 public:
274 StringByteSink(StringClass* dest) : dest_(dest) { }
282 StringByteSink(StringClass* dest, int32_t initialAppendCapacity) : dest_(dest) {
283 if (initialAppendCapacity > 0 &&
284 (uint32_t)initialAppendCapacity > (dest->capacity() - dest->length())) {
285 dest->reserve(dest->length() + initialAppendCapacity);
286 }
287 }
294 virtual void Append(const char* data, int32_t n) override { dest_->append(data, n); }
295 private:
296 StringClass* dest_;
297
298 StringByteSink() = delete;
299 StringByteSink(const StringByteSink &) = delete;
300 StringByteSink &operator=(const StringByteSink &) = delete;
301};
302
303U_NAMESPACE_END
304
305#endif /* U_SHOW_CPLUSPLUS_API */
306
307#endif // __BYTESTREAM_H__
icu::ByteSink
A ByteSink can be filled with bytes.
Definition bytestream.h:53
icu::ByteSink::GetAppendBuffer
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.
icu::ByteSink::AppendU8
void AppendU8(const char *bytes, int32_t n)
Appends n bytes to this.
Definition bytestream.h:85
icu::ByteSink::Append
virtual void Append(const char *bytes, int32_t n)=0
Append "bytes[0,n-1]" to this.
icu::ByteSink::ByteSink
ByteSink()
Default constructor.
Definition bytestream.h:59
icu::ByteSink::AppendU8
void AppendU8(const char8_t *bytes, int32_t n)
Appends n bytes to this.
Definition bytestream.h:101
icu::ByteSink::Flush
virtual void Flush()
Flush internal buffers.
icu::ByteSink::~ByteSink
virtual ~ByteSink()
Virtual destructor.
icu::CheckedArrayByteSink
Implementation of ByteSink that writes to a flat byte array, with bounds-checking: This sink will not...
Definition bytestream.h:180
icu::CheckedArrayByteSink::NumberOfBytesWritten
int32_t NumberOfBytesWritten() const
Returns the number of bytes actually written to the sink.
Definition bytestream.h:233
icu::CheckedArrayByteSink::CheckedArrayByteSink
CheckedArrayByteSink(char *outbuf, int32_t capacity)
Constructs a ByteSink that will write to outbuf[0..capacity-1].
icu::CheckedArrayByteSink::~CheckedArrayByteSink
virtual ~CheckedArrayByteSink()
Destructor.
icu::CheckedArrayByteSink::Reset
virtual CheckedArrayByteSink & Reset()
Returns the sink to its original state, without modifying the buffer.
icu::CheckedArrayByteSink::NumberOfBytesAppended
int32_t NumberOfBytesAppended() const
Returns the number of bytes appended to the sink.
Definition bytestream.h:248
icu::CheckedArrayByteSink::Overflowed
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:240
icu::CheckedArrayByteSink::Append
virtual void Append(const char *bytes, int32_t n) override
Append "bytes[0,n-1]" to this.
icu::CheckedArrayByteSink::GetAppendBuffer
virtual char * GetAppendBuffer(int32_t min_capacity, int32_t desired_capacity_hint, char *scratch, int32_t scratch_capacity, int32_t *result_capacity) override
Returns a writable buffer for appending and writes the buffer's capacity to *result_capacity.
icu::StringByteSink
Implementation of ByteSink that writes to a "string".
Definition bytestream.h:267
icu::StringByteSink::StringByteSink
StringByteSink(StringClass *dest, int32_t initialAppendCapacity)
Constructs a ByteSink that reserves append capacity and will append bytes to the dest string.
Definition bytestream.h:282
icu::StringByteSink::StringByteSink
StringByteSink(StringClass *dest)
Constructs a ByteSink that will append bytes to the dest string.
Definition bytestream.h:274
icu::StringByteSink::Append
virtual void Append(const char *data, int32_t n) override
Append "bytes[0,n-1]" to this.
Definition bytestream.h:294
icu::UMemory
UMemory is the common ICU base class.
Definition uobject.h:115
std_string.h
C++ API: Central ICU header for including the C++ standard <string> header and for related definition...
UBool
int8_t UBool
The ICU boolean type, a signed-byte integer.
Definition umachine.h:247
uobject.h
C++ API: Common ICU base class UObject.
utypes.h
Basic definitions for ICU, for both C and C++ APIs.
U_COMMON_API
#define U_COMMON_API
Set to export library symbols from inside the common library, and to import them from outside.
Definition utypes.h:300