summaryrefslogtreecommitdiff
path: root/Build/source/texk/lcdf-typetools/liblcdf/straccum.cc
blob: e472d3c06d5a53e899e4677c9a774090960bf098 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
// -*- related-file-name: "../include/lcdf/straccum.hh" -*-
/*
 * straccum.{cc,hh} -- build up strings with operator<<
 * Eddie Kohler
 *
 * Copyright (c) 1999-2000 Massachusetts Institute of Technology
 * Copyright (c) 2001-2010 Eddie Kohler
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, subject to the conditions
 * listed in the Click LICENSE file. These conditions include: you must
 * preserve this copyright notice, and you cannot mention the copyright
 * holders in advertising related to the Software without their permission.
 * The Software is provided WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED. This
 * notice is a summary of the Click LICENSE file; the license in that file is
 * legally binding.
 */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <lcdf/straccum.hh>
#include <lcdf/vector.hh>
#include <stdarg.h>
#include <stdio.h>
#include <ctype.h>

/** @class StringAccum
 * @brief Efficiently build up Strings from pieces.
 *
 * Like the String class, StringAccum represents a string of characters.
 * However, unlike a String, a StringAccum is inherently mutable, and
 * efficiently supports building up a large string from many smaller pieces.
 *
 * StringAccum objects support operator<<() operations for most fundamental
 * data types.  A StringAccum is generally built up by operator<<(), and then
 * turned into a String by the take_string() method.  Extracting the String
 * from a StringAccum does no memory allocation or copying; the StringAccum's
 * memory is donated to the String.
 *
 * <h3>Out-of-memory StringAccums</h3>
 *
 * When there is not enough memory to add requested characters to a
 * StringAccum object, the object becomes a special "out-of-memory"
 * StringAccum.  Out-of-memory objects are contagious: the result of any
 * concatenation operation involving an out-of-memory StringAccum is another
 * out-of-memory StringAccum.  Appending an out-of-memory String with "sa <<
 * s" makes "sa" out-of-memory.  (However, other usually-equivalent calls,
 * such as "sa.append(s.begin(), s.end())", <em>do not</em> make "sa"
 * out-of-memory.)  Calling take_string() on an out-of-memory StringAccum
 * returns an out-of-memory String.
 *
 * Out-of-memory StringAccum objects have length zero.
 */


void
StringAccum::assign_out_of_memory()
{
    assert(_cap >= 0);
    if (_cap > 0)
	delete[] (_s - MEMO_SPACE);
    _s = reinterpret_cast<unsigned char *>(const_cast<char *>(String::out_of_memory_data()));
    _cap = -1;
    _len = 0;
}

bool
StringAccum::grow(int want)
{
    // can't append to out-of-memory strings
    if (_cap < 0)
	return false;

    int ncap = (_cap ? (_cap + MEMO_SPACE) * 2 : 128) - MEMO_SPACE;
    while (ncap <= want)
	ncap = (ncap + MEMO_SPACE) * 2 - MEMO_SPACE;

    unsigned char *n = new unsigned char[ncap + MEMO_SPACE];
    if (!n) {
	assign_out_of_memory();
	return false;
    }
    n += MEMO_SPACE;

    if (_s) {
	memcpy(n, _s, _cap);
	delete[] (_s - MEMO_SPACE);
    }
    _s = n;
    _cap = ncap;
    return true;
}

void
StringAccum::append_fill(int c, int len)
{
    if (char *s = extend(len))
	memset(s, c, len);
}

void
StringAccum::append_utf8_hard(unsigned ch)
{
    if (ch < 0x80)
	append((unsigned char) ch);
    else if (ch < 0x800) {
	append((unsigned char) (0xC0 + ((ch >> 6) & 0x1F)));
	append((unsigned char) (0x80 + (ch & 0x3F)));
    } else if (ch < 0x10000) {
	append((unsigned char) (0xE0 + ((ch >> 12) & 0x0F)));
	append((unsigned char) (0x80 + ((ch >> 6) & 0x3F)));
	append((unsigned char) (0x80 + (ch & 0x3F)));
    } else if (ch < 0x110000) {
	append((unsigned char) (0xF0 + ((ch >> 18) & 0x07)));
	append((unsigned char) (0x80 + ((ch >> 12) & 0x3F)));
	append((unsigned char) (0x80 + ((ch >> 6) & 0x3F)));
	append((unsigned char) (0x80 + (ch & 0x3F)));
    } else
	append((unsigned char) '?');
}

const char *
StringAccum::c_str()
{
    if (_len < _cap || grow(_len))
	_s[_len] = '\0';
    return reinterpret_cast<char *>(_s);
}

void
StringAccum::append_internal_data(const char *s, int len)
{
    if (out_of_memory())
	/* do nothing */;
    else if (!_s || _len + len <= _cap)
	append_external_data(s, len);
    else {
	unsigned char *old_s = _s;
	int old_len = _len;
	int old_cap = _cap;

	_s = 0;
	_len = 0;
	_cap = 0;

	if (char *new_s = extend(old_len + len)) {
	    memcpy(new_s, old_s, old_len);
	    memcpy(new_s + old_len, s, len);
	}

	delete[] (old_s - MEMO_SPACE);
    }
}

String
StringAccum::take_string()
{
    int len = length();
    int cap = _cap;
    char *str = reinterpret_cast<char *>(_s);
    if (len > 0) {
	_s = 0;
	_len = _cap = 0;
	return String::make_claim(str, len, cap);
    } else if (!out_of_memory())
	return String();
    else {
	clear();
	return String::make_out_of_memory();
    }
}

void
StringAccum::swap(StringAccum &o)
{
    unsigned char *os = o._s;
    int olen = o._len, ocap = o._cap;
    o._s = _s;
    o._len = _len, o._cap = _cap;
    _s = os;
    _len = olen, _cap = ocap;
}

/** @relates StringAccum
    @brief Append decimal representation of @a i to @a sa.
    @return @a sa */
StringAccum &
operator<<(StringAccum &sa, long i)
{
    if (char *x = sa.reserve(24)) {
	int len = sprintf(x, "%ld", i);
	sa.adjust_length(len);
    }
    return sa;
}

/** @relates StringAccum
    @brief Append decimal representation of @a u to @a sa.
    @return @a sa */
StringAccum &
operator<<(StringAccum &sa, unsigned long u)
{
    if (char *x = sa.reserve(24)) {
	int len = sprintf(x, "%lu", u);
	sa.adjust_length(len);
    }
    return sa;
}

StringAccum &
operator<<(StringAccum &sa, double d)
{
    if (char *x = sa.reserve(256)) {
	int len = sprintf(x, "%.12g", d);
	sa.adjust_length(len);
    }
    return sa;
}

StringAccum &
StringAccum::snprintf(int n, const char *format, ...)
{
    va_list val;
    va_start(val, format);
    if (char *x = reserve(n + 1)) {
#if HAVE_VSNPRINTF
	int len = vsnprintf(x, n + 1, format, val);
#else
	int len = vsprintf(x, format, val);
	assert(len <= n);
#endif
	adjust_length(len);
    }
    va_end(val);
    return *this;
}

void
StringAccum::append_break_lines(const String& text, int linelen, const String &leftmargin)
{
    if (text.length() == 0)
	return;
    const char* line = text.begin();
    const char* ends = text.end();
    linelen -= leftmargin.length();
    for (const char* s = line; s < ends; s++) {
	const char* start = s;
	while (s < ends && isspace((unsigned char) *s))
	    s++;
	const char* word = s;
	while (s < ends && !isspace((unsigned char) *s))
	    s++;
	if (s - line > linelen && start > line) {
	    *this << leftmargin;
	    append(line, start - line);
	    *this << '\n';
	    line = word;
	}
    }
    if (line < text.end()) {
	*this << leftmargin;
	append(line, text.end() - line);
	*this << '\n';
    }
}