From 84d20d9e433028125bfe36557ad54a28b97914b2 Mon Sep 17 00:00:00 2001 From: Max Kellermann Date: Tue, 15 Oct 2013 10:28:52 +0200 Subject: util/FifoBuffer: C++ version of the fifo_buffer library --- Makefile.am | 2 + src/InotifySource.cxx | 30 ++++------ src/InotifySource.hxx | 6 +- src/TextInputStream.cxx | 46 ++++++--------- src/TextInputStream.hxx | 14 ++--- src/event/BufferedSocket.cxx | 49 ++++------------ src/event/BufferedSocket.hxx | 16 ++++-- src/util/FifoBuffer.hxx | 132 +++++++++++++++++++++++++++++++++++++++++++ src/util/WritableBuffer.hxx | 87 ++++++++++++++++++++++++++++ test/run_convert.cxx | 33 +++++------ 10 files changed, 294 insertions(+), 121 deletions(-) create mode 100644 src/util/FifoBuffer.hxx create mode 100644 src/util/WritableBuffer.hxx diff --git a/Makefile.am b/Makefile.am index 064c181c2..cd83b14a9 100644 --- a/Makefile.am +++ b/Makefile.am @@ -256,6 +256,8 @@ libutil_a_SOURCES = \ src/util/Manual.hxx \ src/util/RefCount.hxx \ src/util/fifo_buffer.c src/util/fifo_buffer.h \ + src/util/FifoBuffer.hxx \ + src/util/WritableBuffer.hxx \ src/util/growing_fifo.c src/util/growing_fifo.h \ src/util/LazyRandomEngine.cxx src/util/LazyRandomEngine.hxx \ src/util/SliceBuffer.hxx \ diff --git a/src/InotifySource.cxx b/src/InotifySource.cxx index 587625d3d..bf292af60 100644 --- a/src/InotifySource.cxx +++ b/src/InotifySource.cxx @@ -20,7 +20,6 @@ #include "config.h" #include "InotifySource.hxx" #include "InotifyDomain.hxx" -#include "util/fifo_buffer.h" #include "util/Error.hxx" #include "system/fd_util.h" #include "system/FatalError.hxx" @@ -34,30 +33,27 @@ bool InotifySource::OnSocketReady(gcc_unused unsigned flags) { - void *dest; - size_t length; - ssize_t nbytes; - - dest = fifo_buffer_write(buffer, &length); - if (dest == NULL) + const auto dest = buffer.Write(); + if (dest.IsEmpty()) FatalError("buffer full"); - nbytes = read(Get(), dest, length); + ssize_t nbytes = read(Get(), dest.data, dest.size); if (nbytes < 0) FatalSystemError("Failed to read from inotify"); if (nbytes == 0) FatalError("end of file from inotify"); - fifo_buffer_append(buffer, nbytes); + buffer.Append(nbytes); while (true) { const char *name; + auto range = buffer.Read(); const struct inotify_event *event = (const struct inotify_event *) - fifo_buffer_read(buffer, &length); - if (event == NULL || length < sizeof(*event) || - length < sizeof(*event) + event->len) + range.data; + if (range.size < sizeof(*event) || + range.size < sizeof(*event) + event->len) break; if (event->len > 0 && event->name[event->len - 1] == 0) @@ -66,7 +62,7 @@ InotifySource::OnSocketReady(gcc_unused unsigned flags) name = NULL; callback(event->wd, event->mask, name, callback_ctx); - fifo_buffer_consume(buffer, sizeof(*event) + event->len); + buffer.Consume(sizeof(*event) + event->len); } return true; @@ -77,8 +73,7 @@ InotifySource::InotifySource(EventLoop &_loop, mpd_inotify_callback_t _callback, void *_ctx, int _fd) :SocketMonitor(_fd, _loop), - callback(_callback), callback_ctx(_ctx), - buffer(fifo_buffer_new(4096)) + callback(_callback), callback_ctx(_ctx) { ScheduleRead(); @@ -98,11 +93,6 @@ InotifySource::Create(EventLoop &loop, return new InotifySource(loop, callback, callback_ctx, fd); } -InotifySource::~InotifySource() -{ - fifo_buffer_free(buffer); -} - int InotifySource::Add(const char *path_fs, unsigned mask, Error &error) { diff --git a/src/InotifySource.hxx b/src/InotifySource.hxx index 1fe840c12..f6ddea966 100644 --- a/src/InotifySource.hxx +++ b/src/InotifySource.hxx @@ -21,6 +21,7 @@ #define MPD_INOTIFY_SOURCE_HXX #include "event/SocketMonitor.hxx" +#include "util/FifoBuffer.hxx" #include "Compiler.h" class Error; @@ -32,7 +33,7 @@ class InotifySource final : private SocketMonitor { mpd_inotify_callback_t callback; void *callback_ctx; - struct fifo_buffer *buffer; + FifoBuffer buffer; InotifySource(EventLoop &_loop, mpd_inotify_callback_t callback, void *ctx, int fd); @@ -49,9 +50,6 @@ public: void *ctx, Error &error); - ~InotifySource(); - - /** * Adds a path to the notify list. * diff --git a/src/TextInputStream.cxx b/src/TextInputStream.cxx index d58a2fbee..a69e1d513 100644 --- a/src/TextInputStream.cxx +++ b/src/TextInputStream.cxx @@ -29,35 +29,23 @@ #include #include -TextInputStream::TextInputStream(struct input_stream *_is) - : is(_is), - buffer(fifo_buffer_new(4096)) -{ -} - -TextInputStream::~TextInputStream() -{ - fifo_buffer_free(buffer); -} - bool TextInputStream::ReadLine(std::string &line) { - void *dest; const char *src, *p; - size_t length, nbytes; do { - dest = fifo_buffer_write(buffer, &length); - if (dest != nullptr && length >= 2) { + size_t nbytes; + auto dest = buffer.Write(); + if (dest.size >= 2) { /* reserve one byte for the null terminator if the last line is not terminated by a newline character */ - --length; + --dest.size; Error error; - nbytes = is->LockRead(dest, length, error); + nbytes = is->LockRead(dest.data, dest.size, error); if (nbytes > 0) - fifo_buffer_append(buffer, nbytes); + buffer.Append(nbytes); else if (error.IsDefined()) { LogError(error); return false; @@ -65,28 +53,28 @@ bool TextInputStream::ReadLine(std::string &line) } else nbytes = 0; - auto src_p = fifo_buffer_read(buffer, &length); - src = reinterpret_cast(src_p); - - if (src == nullptr) + auto src_p = buffer.Read(); + if (src_p.IsEmpty()) return false; - p = reinterpret_cast(memchr(src, '\n', length)); + src = src_p.data; + + p = reinterpret_cast(memchr(src, '\n', src_p.size)); if (p == nullptr && nbytes == 0) { /* end of file (or line too long): terminate the current line */ - dest = fifo_buffer_write(buffer, &nbytes); - assert(dest != nullptr); - *(char *)dest = '\n'; - fifo_buffer_append(buffer, 1); + dest = buffer.Write(); + assert(!dest.IsEmpty()); + dest.data[0] = '\n'; + buffer.Append(1); } } while (p == nullptr); - length = p - src + 1; + size_t length = p - src + 1; while (p > src && g_ascii_isspace(p[-1])) --p; line = std::string(src, p - src); - fifo_buffer_consume(buffer, length); + buffer.Consume(length); return true; } diff --git a/src/TextInputStream.hxx b/src/TextInputStream.hxx index 2608184e2..f3d87c90a 100644 --- a/src/TextInputStream.hxx +++ b/src/TextInputStream.hxx @@ -20,6 +20,8 @@ #ifndef MPD_TEXT_INPUT_STREAM_HXX #define MPD_TEXT_INPUT_STREAM_HXX +#include "util/FifoBuffer.hxx" + #include struct input_stream; @@ -27,7 +29,8 @@ struct fifo_buffer; class TextInputStream { struct input_stream *is; - struct fifo_buffer *buffer; + FifoBuffer buffer; + public: /** * Wraps an existing #input_stream object into a #TextInputStream, @@ -35,13 +38,8 @@ public: * * @param _is an open #input_stream object */ - explicit TextInputStream(struct input_stream *_is); - - /** - * Frees the #TextInputStream object. Does not close or free the - * underlying #input_stream. - */ - ~TextInputStream(); + explicit TextInputStream(struct input_stream *_is) + :is(_is) {} TextInputStream(const TextInputStream &) = delete; TextInputStream& operator=(const TextInputStream &) = delete; diff --git a/src/event/BufferedSocket.cxx b/src/event/BufferedSocket.cxx index f333a5987..92e350e85 100644 --- a/src/event/BufferedSocket.cxx +++ b/src/event/BufferedSocket.cxx @@ -20,20 +20,9 @@ #include "config.h" #include "BufferedSocket.hxx" #include "system/SocketError.hxx" -#include "util/fifo_buffer.h" #include "util/Error.hxx" #include "util/Domain.hxx" -#include -#include -#include - -BufferedSocket::~BufferedSocket() -{ - if (input != nullptr) - fifo_buffer_free(input); -} - BufferedSocket::ssize_t BufferedSocket::DirectRead(void *data, size_t length) { @@ -62,16 +51,12 @@ BufferedSocket::ReadToBuffer() { assert(IsDefined()); - if (input == nullptr) - input = fifo_buffer_new(8192); - - size_t length; - void *buffer = fifo_buffer_write(input, &length); - assert(buffer != nullptr); + const auto buffer = input.Write(); + assert(!buffer.IsEmpty()); - const auto nbytes = DirectRead(buffer, length); + const auto nbytes = DirectRead(buffer.data, buffer.size); if (nbytes > 0) - fifo_buffer_append(input, nbytes); + input.Append(nbytes); return nbytes >= 0; } @@ -81,23 +66,17 @@ BufferedSocket::ResumeInput() { assert(IsDefined()); - if (input == nullptr) { - ScheduleRead(); - return true; - } - while (true) { - size_t length; - const void *data = fifo_buffer_read(input, &length); - if (data == nullptr) { + const auto buffer = input.Read(); + if (buffer.IsEmpty()) { ScheduleRead(); return true; } - const auto result = OnSocketInput(data, length); + const auto result = OnSocketInput(buffer.data, buffer.size); switch (result) { case InputResult::MORE: - if (fifo_buffer_is_full(input)) { + if (input.IsFull()) { // TODO static constexpr Domain buffered_socket_domain("buffered_socket"); Error error; @@ -123,14 +102,6 @@ BufferedSocket::ResumeInput() } } -void -BufferedSocket::ConsumeInput(size_t nbytes) -{ - assert(IsDefined()); - - fifo_buffer_consume(input, nbytes); -} - bool BufferedSocket::OnSocketReady(unsigned flags) { @@ -142,12 +113,12 @@ BufferedSocket::OnSocketReady(unsigned flags) } if (flags & READ) { - assert(input == nullptr || !fifo_buffer_is_full(input)); + assert(!input.IsFull()); if (!ReadToBuffer() || !ResumeInput()) return false; - if (input == nullptr || !fifo_buffer_is_full(input)) + if (input.IsFull()) ScheduleRead(); } diff --git a/src/event/BufferedSocket.hxx b/src/event/BufferedSocket.hxx index 578000961..31d6c3c57 100644 --- a/src/event/BufferedSocket.hxx +++ b/src/event/BufferedSocket.hxx @@ -22,8 +22,12 @@ #include "check.h" #include "SocketMonitor.hxx" +#include "util/FifoBuffer.hxx" #include "Compiler.h" +#include +#include + struct fifo_buffer; class Error; @@ -31,16 +35,14 @@ class Error; * A #SocketMonitor specialization that adds an input buffer. */ class BufferedSocket : protected SocketMonitor { - fifo_buffer *input; + FifoBuffer input; public: BufferedSocket(int _fd, EventLoop &_loop) - :SocketMonitor(_fd, _loop), input(nullptr) { + :SocketMonitor(_fd, _loop) { ScheduleRead(); } - ~BufferedSocket(); - using SocketMonitor::IsDefined; using SocketMonitor::Close; using SocketMonitor::Write; @@ -67,7 +69,11 @@ protected: * does not invalidate the pointer passed to OnSocketInput() * yet. */ - void ConsumeInput(size_t nbytes); + void ConsumeInput(size_t nbytes) { + assert(IsDefined()); + + input.Consume(nbytes); + } enum class InputResult { /** diff --git a/src/util/FifoBuffer.hxx b/src/util/FifoBuffer.hxx new file mode 100644 index 000000000..75d2d2ef2 --- /dev/null +++ b/src/util/FifoBuffer.hxx @@ -0,0 +1,132 @@ +/* + * Copyright (C) 2003-2010 Max Kellermann + * + * 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 FIFO_BUFFER_HPP +#define FIFO_BUFFER_HPP + +#include "WritableBuffer.hxx" + +#include +#include + +#include +#include + +/** + * A first-in-first-out buffer: you can append data at the end, and + * read data from the beginning. This class automatically shifts the + * buffer as needed. It is not thread safe. + */ +template +class FifoBuffer { +public: + typedef size_t size_type; + +public: + typedef WritableBuffer Range; + +protected: + size_type head, tail; + T data[size]; + +public: + constexpr + FifoBuffer():head(0), tail(0) {} + +protected: + void Shift() { + if (head == 0) + return; + + assert(head <= size); + assert(tail <= size); + assert(tail >= head); + + std::move(data + head, data + tail, data); + + tail -= head; + head = 0; + } + +public: + void Clear() { + head = tail = 0; + } + + bool IsEmpty() const { + return head == tail; + } + + bool IsFull() const { + return head == 0 && tail == size; + } + + /** + * Prepares writing. Returns a buffer range which may be written. + * When you are finished, call append(). + */ + Range Write() { + Shift(); + return Range(data + tail, size - tail); + } + + /** + * Expands the tail of the buffer, after data has been written to + * the buffer returned by write(). + */ + void Append(size_type n) { + assert(tail <= size); + assert(n <= size); + assert(tail + n <= size); + + tail += n; + } + + /** + * Return a buffer range which may be read. The buffer pointer is + * writable, to allow modifications while parsing. + */ + Range Read() { + return Range(data + head, tail - head); + } + + /** + * Marks a chunk as consumed. + */ + void Consume(size_type n) { + assert(tail <= size); + assert(head <= tail); + assert(n <= tail); + assert(head + n <= tail); + + head += n; + } +}; + +#endif diff --git a/src/util/WritableBuffer.hxx b/src/util/WritableBuffer.hxx new file mode 100644 index 000000000..4e529cfad --- /dev/null +++ b/src/util/WritableBuffer.hxx @@ -0,0 +1,87 @@ +/* + * Copyright (C) 2013 Max Kellermann + * + * 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 WRITABLE_BUFFER_HPP +#define WRITABLE_BUFFER_HPP + +#include "Compiler.h" + +#include + +/** + * A reference to a memory area that is writable. + * + * @see ConstBuffer + */ +template +struct WritableBuffer { + typedef size_t size_type; + typedef T *pointer_type; + typedef const T *const_pointer_type; + typedef pointer_type iterator; + typedef const_pointer_type const_iterator; + + pointer_type data; + size_type size; + + WritableBuffer() = default; + + constexpr WritableBuffer(pointer_type _data, size_type _size) + :data(_data), size(_size) {} + + constexpr static WritableBuffer Null() { + return { nullptr, 0 }; + } + + constexpr bool IsNull() const { + return data == nullptr; + } + + constexpr bool IsEmpty() const { + return size == 0; + } + + constexpr iterator begin() const { + return data; + } + + constexpr iterator end() const { + return data + size; + } + + constexpr const_iterator cbegin() const { + return data; + } + + constexpr const_iterator cend() const { + return data + size; + } +}; + +#endif diff --git a/test/run_convert.cxx b/test/run_convert.cxx index 939e279d0..ca55bcc0b 100644 --- a/test/run_convert.cxx +++ b/test/run_convert.cxx @@ -28,7 +28,7 @@ #include "AudioFormat.hxx" #include "pcm/PcmConvert.hxx" #include "ConfigGlobal.hxx" -#include "util/fifo_buffer.h" +#include "util/FifoBuffer.hxx" #include "util/Error.hxx" #include "stdbin.h" @@ -59,8 +59,6 @@ int main(int argc, char **argv) { AudioFormat in_audio_format, out_audio_format; const void *output; - ssize_t nbytes; - size_t length; if (argc != 3) { g_printerr("Usage: run_convert IN_FORMAT OUT_FORMAT OUT\n"); @@ -92,28 +90,31 @@ int main(int argc, char **argv) PcmConvert state; - struct fifo_buffer *buffer = fifo_buffer_new(4096); + FifoBuffer buffer; while (true) { - void *p = fifo_buffer_write(buffer, &length); - assert(p != NULL); + { + const auto dest = buffer.Write(); + assert(!dest.IsEmpty()); - nbytes = read(0, p, length); - if (nbytes <= 0) - break; + ssize_t nbytes = read(0, dest.data, dest.size); + if (nbytes <= 0) + break; - fifo_buffer_append(buffer, nbytes); + buffer.Append(nbytes); + } - const void *src = fifo_buffer_read(buffer, &length); - assert(src != NULL); + auto src = buffer.Read(); + assert(!src.IsEmpty()); - length -= length % in_frame_size; - if (length == 0) + src.size -= src.size % in_frame_size; + if (src.IsEmpty()) continue; - fifo_buffer_consume(buffer, length); + buffer.Consume(src.size); - output = state.Convert(in_audio_format, src, length, + size_t length; + output = state.Convert(in_audio_format, src.data, src.size, out_audio_format, &length, error); if (output == NULL) { g_printerr("Failed to convert: %s\n", error.GetMessage()); -- cgit v1.2.3