aboutsummaryrefslogtreecommitdiff
path: root/src/util/PeakBuffer.cxx
blob: a3659b8f4bb6fa71651933f35c2769e04d269323 (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
/*
 * Copyright (C) 2003-2013 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "PeakBuffer.hxx"
#include "HugeAllocator.hxx"
#include "fifo_buffer.h"

#include <algorithm>

#include <assert.h>
#include <stdint.h>
#include <string.h>

PeakBuffer::~PeakBuffer()
{
	if (normal_buffer != nullptr)
		fifo_buffer_free(normal_buffer);

	if (peak_buffer != nullptr)
		HugeFree(peak_buffer, peak_size);
}

bool
PeakBuffer::IsEmpty() const
{
	return (normal_buffer == nullptr ||
		fifo_buffer_is_empty(normal_buffer)) &&
		(peak_buffer == nullptr ||
		 fifo_buffer_is_empty(peak_buffer));
}

const void *
PeakBuffer::Read(size_t *length_r) const
{
	if (normal_buffer != nullptr) {
		const void *p = fifo_buffer_read(normal_buffer, length_r);
		if (p != nullptr)
			return p;
	}

	if (peak_buffer != nullptr) {
		const void *p = fifo_buffer_read(peak_buffer, length_r);
		if (p != nullptr)
			return p;
	}

	return nullptr;
}

void
PeakBuffer::Consume(size_t length)
{
	if (normal_buffer != nullptr && !fifo_buffer_is_empty(normal_buffer)) {
		fifo_buffer_consume(normal_buffer, length);
		return;
	}

	if (peak_buffer != nullptr && !fifo_buffer_is_empty(peak_buffer)) {
		fifo_buffer_consume(peak_buffer, length);
		if (fifo_buffer_is_empty(peak_buffer)) {
			HugeFree(peak_buffer, peak_size);
			peak_buffer = nullptr;
		}

		return;
	}
}

static size_t
AppendTo(fifo_buffer *buffer, const void *data, size_t length)
{
	assert(data != nullptr);
	assert(length > 0);

	size_t total = 0;

	do {
		size_t max_length;
		void *p = fifo_buffer_write(buffer, &max_length);
		if (p == nullptr)
			break;

		const size_t nbytes = std::min(length, max_length);
		memcpy(p, data, nbytes);
		fifo_buffer_append(buffer, nbytes);

		data = (const uint8_t *)data + nbytes;
		length -= nbytes;
		total += nbytes;
	} while (length > 0);

	return total;
}

bool
PeakBuffer::Append(const void *data, size_t length)
{
	if (length == 0)
		return true;

	if (peak_buffer != nullptr && !fifo_buffer_is_empty(peak_buffer)) {
		size_t nbytes = AppendTo(peak_buffer, data, length);
		return nbytes == length;
	}

	if (normal_buffer == nullptr)
		normal_buffer = fifo_buffer_new(normal_size);

	size_t nbytes = AppendTo(normal_buffer, data, length);
	if (nbytes > 0) {
		data = (const uint8_t *)data + nbytes;
		length -= nbytes;
		if (length == 0)
			return true;
	}

	if (peak_buffer == nullptr && peak_size > 0) {
		peak_buffer = (fifo_buffer *)HugeAllocate(peak_size);
		if (peak_buffer == nullptr)
			return false;

		fifo_buffer_init(peak_buffer, peak_size);
	}

	nbytes = AppendTo(peak_buffer, data, length);
	return nbytes == length;
}