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authorMax Kellermann <max@duempel.org>2013-08-07 18:46:58 +0200
committerMax Kellermann <max@duempel.org>2013-08-07 18:51:21 +0200
commit44a0e21795dcbd94d45ff143123f8b085754ea81 (patch)
treede7572fad77f000357c6970360cfb5319aa8a64a /src
parentfafaf567f94ed08c04bd9aca73714aa3293854bc (diff)
downloadmpd-44a0e21795dcbd94d45ff143123f8b085754ea81.tar.gz
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PcmBuffer: move code to new class ReusableBuffer
ReusableBuffer is more generic.
Diffstat (limited to 'src')
-rw-r--r--src/pcm/PcmBuffer.cxx25
-rw-r--r--src/pcm/PcmBuffer.hxx23
-rw-r--r--src/pcm/PcmChannels.hxx2
-rw-r--r--src/pcm/PcmDsdUsb.hxx2
-rw-r--r--src/pcm/PcmFormat.hxx2
-rw-r--r--src/util/ReusableArray.hxx88
6 files changed, 98 insertions, 44 deletions
diff --git a/src/pcm/PcmBuffer.cxx b/src/pcm/PcmBuffer.cxx
index adfd0e518..6ace399f3 100644
--- a/src/pcm/PcmBuffer.cxx
+++ b/src/pcm/PcmBuffer.cxx
@@ -21,16 +21,6 @@
#include "PcmBuffer.hxx"
#include "poison.h"
-/**
- * Align the specified size to the next 8k boundary.
- */
-constexpr
-static size_t
-align_8k(size_t size)
-{
- return ((size - 1) | 0x1fff) + 1;
-}
-
void *
PcmBuffer::Get(size_t new_size)
{
@@ -39,18 +29,5 @@ PcmBuffer::Get(size_t new_size)
be an error condition */
new_size = 1;
- if (size < new_size) {
- /* free the old buffer */
- g_free(buffer);
-
- size = align_8k(new_size);
- buffer = g_malloc(size);
- } else {
- /* discard old buffer contents */
- poison_undefined(buffer, size);
- }
-
- assert(size >= new_size);
-
- return buffer;
+ return buffer.Get(new_size);
}
diff --git a/src/pcm/PcmBuffer.hxx b/src/pcm/PcmBuffer.hxx
index ae7030f76..2eddfb7f9 100644
--- a/src/pcm/PcmBuffer.hxx
+++ b/src/pcm/PcmBuffer.hxx
@@ -20,33 +20,22 @@
#ifndef PCM_BUFFER_HXX
#define PCM_BUFFER_HXX
-#include "check.h"
+#include "util/ReusableArray.hxx"
#include "gcc.h"
-#include <glib.h>
-
-#include <assert.h>
+#include <stdint.h>
/**
* Manager for a temporary buffer which grows as needed. We could
* allocate a new buffer every time pcm_convert() is called, but that
* would put too much stress on the allocator.
*/
-struct PcmBuffer {
- void *buffer;
-
- size_t size;
-
- PcmBuffer():buffer(nullptr), size(0) {}
-
- ~PcmBuffer() {
- g_free(buffer);
- }
+class PcmBuffer {
+ ReusableArray<uint8_t, 8192> buffer;
+public:
void Clear() {
- g_free(buffer);
- buffer = nullptr;
- size = 0;
+ buffer.Clear();
}
/**
diff --git a/src/pcm/PcmChannels.hxx b/src/pcm/PcmChannels.hxx
index 889a14a60..c67822825 100644
--- a/src/pcm/PcmChannels.hxx
+++ b/src/pcm/PcmChannels.hxx
@@ -23,7 +23,7 @@
#include <stdint.h>
#include <stddef.h>
-struct PcmBuffer;
+class PcmBuffer;
/**
* Changes the number of channels in 16 bit PCM data.
diff --git a/src/pcm/PcmDsdUsb.hxx b/src/pcm/PcmDsdUsb.hxx
index 2cf8bfbba..3b7121465 100644
--- a/src/pcm/PcmDsdUsb.hxx
+++ b/src/pcm/PcmDsdUsb.hxx
@@ -25,7 +25,7 @@
#include <stdint.h>
#include <stddef.h>
-struct PcmBuffer;
+class PcmBuffer;
/**
* Pack DSD 1 bit samples into (padded) 24 bit PCM samples for
diff --git a/src/pcm/PcmFormat.hxx b/src/pcm/PcmFormat.hxx
index b18b4f932..cc44d6dd5 100644
--- a/src/pcm/PcmFormat.hxx
+++ b/src/pcm/PcmFormat.hxx
@@ -25,7 +25,7 @@
#include <stdint.h>
#include <stddef.h>
-struct PcmBuffer;
+class PcmBuffer;
class PcmDither;
/**
diff --git a/src/util/ReusableArray.hxx b/src/util/ReusableArray.hxx
new file mode 100644
index 000000000..30b1a9cd9
--- /dev/null
+++ b/src/util/ReusableArray.hxx
@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2013 Max Kellermann <max@duempel.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef REUSABLE_ARRAY_HXX
+#define REUSABLE_ARRAY_HXX
+
+#include <stddef.h>
+
+#include "gcc.h"
+
+/**
+ * Manager for a temporary array which grows as needed. This attempts
+ * to reduce the number of consecutive heap allocations and
+ * deallocations.
+ *
+ * @param T the array element type
+ * @param M always allocate multiples of this number; must be a power of 2
+ */
+template<typename T, size_t M=1>
+class ReusableArray {
+ T *buffer;
+ size_t capacity;
+
+public:
+ ReusableArray():buffer(nullptr), capacity(0) {}
+
+ ReusableArray(const ReusableArray &other) = delete;
+ ReusableArray &operator=(const ReusableArray &other) = delete;
+
+ ~ReusableArray() {
+ delete[] buffer;
+ }
+
+ /**
+ * Free resources allocated by this object. This invalidates
+ * the buffer returned by Get().
+ */
+ void Clear() {
+ delete[] buffer;
+ buffer = nullptr;
+ capacity = 0;
+ }
+
+ /**
+ * Get the buffer, and guarantee a minimum size. This buffer
+ * becomes invalid with the next Get() call.
+ */
+ gcc_malloc
+ T *Get(size_t size) {
+ if (gcc_unlikely(size > capacity)) {
+ /* too small: grow */
+ delete[] buffer;
+
+ capacity = ((size - 1) | (M - 1)) + 1;
+ buffer = new T[capacity];
+ }
+
+ return buffer;
+ }
+};
+
+#endif