ICU 65.1 65.1

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
42 #if U_SHOW_CPLUSPLUS_API
43
44 #include "unicode/uobject.h"
45 #include "unicode/std_string.h"
46
47 U_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
116 virtual char* GetAppendBuffer(int32_t min_capacity,
117 int32_t desired_capacity_hint,
118 char* scratch, int32_t scratch_capacity,
119 int32_t* result_capacity);
120
129 virtual void Flush();
130
131 private:
132 ByteSink(const ByteSink &) = delete;
133 ByteSink &operator=(const ByteSink &) = delete;
134 };
135
136 // -------------------------------------------------------------
137 // Some standard implementations
138
148 class U_COMMON_API CheckedArrayByteSink : public ByteSink {
149 public:
156 CheckedArrayByteSink(char* outbuf, int32_t capacity);
161 virtual ~CheckedArrayByteSink();
170 virtual CheckedArrayByteSink& Reset();
177 virtual void Append(const char* bytes, int32_t n);
192 virtual char* GetAppendBuffer(int32_t min_capacity,
193 int32_t desired_capacity_hint,
194 char* scratch, int32_t scratch_capacity,
195 int32_t* result_capacity);
201 int32_t NumberOfBytesWritten() const { return size_; }
208 UBool Overflowed() const { return overflowed_; }
216 int32_t NumberOfBytesAppended() const { return appended_; }
217 private:
218 char* outbuf_;
219 const int32_t capacity_;
220 int32_t size_;
221 int32_t appended_;
222 UBool overflowed_;
223
224 CheckedArrayByteSink() = delete;
225 CheckedArrayByteSink(const CheckedArrayByteSink &) = delete;
226 CheckedArrayByteSink &operator=(const CheckedArrayByteSink &) = delete;
227 };
228
234 template<typename StringClass>
235 class StringByteSink : public ByteSink {
236 public:
242 StringByteSink(StringClass* dest) : dest_(dest) { }
250 StringByteSink(StringClass* dest, int32_t initialAppendCapacity) : dest_(dest) {
251 if (initialAppendCapacity > 0 &&
252 (uint32_t)initialAppendCapacity > (dest->capacity() - dest->length())) {
253 dest->reserve(dest->length() + initialAppendCapacity);
254 }
255 }
262 virtual void Append(const char* data, int32_t n) { dest_->append(data, n); }
263 private:
264 StringClass* dest_;
265
266 StringByteSink() = delete;
267 StringByteSink(const StringByteSink &) = delete;
268 StringByteSink &operator=(const StringByteSink &) = delete;
269 };
270
271 U_NAMESPACE_END
272
273 #endif /* U_SHOW_CPLUSPLUS_API */
274
275 #endif // __BYTESTREAM_H__
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&#39;s capacity to *result_capacity.
icu::StringByteSink::StringByteSink
StringByteSink(StringClass *dest)
Constructs a ByteSink that will append bytes to the dest string.
Definition: bytestream.h:242
icu::CheckedArrayByteSink::NumberOfBytesWritten
int32_t NumberOfBytesWritten() const
Returns the number of bytes actually written to the sink.
Definition: bytestream.h:201
icu::StringByteSink::Append
virtual void Append(const char *data, int32_t n)
Append "bytes[0,n-1]" to this.
Definition: bytestream.h:262
icu::ByteSink::ByteSink
ByteSink()
Default constructor.
Definition: bytestream.h:59
icu::ByteSink
A ByteSink can be filled with bytes.
Definition: bytestream.h:53
icu::CheckedArrayByteSink::Overflowed
UBool Overflowed() const
Returns true if any bytes were discarded, i.e., if there was an attempt to write more than &#39;capacity&#39;...
Definition: bytestream.h:208
icu::CheckedArrayByteSink::NumberOfBytesAppended
int32_t NumberOfBytesAppended() const
Returns the number of bytes appended to the sink.
Definition: bytestream.h:216
icu::ByteSink::Append
virtual void Append(const char *bytes, int32_t n)=0
Append "bytes[0,n-1]" to this.
icu::CheckedArrayByteSink
Implementation of ByteSink that writes to a flat byte array, with bounds-checking: This sink will not...
Definition: bytestream.h:148
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:250
std_string.h
C++ API: Central ICU header for including the C++ standard <string> header and for related definition...
uobject.h
C++ API: Common ICU base class UObject.
utypes.h
Basic definitions for ICU, for both C and C++ APIs.
icu::StringByteSink
Implementation of ByteSink that writes to a "string".
Definition: bytestream.h:235
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
icu::UMemory
UMemory is the common ICU base class.
Definition: uobject.h:115
UBool
int8_t UBool
The ICU boolean type.
Definition: umachine.h:261