diff options
Diffstat (limited to 'src/input/RewindInputPlugin.cxx')
-rw-r--r-- | src/input/RewindInputPlugin.cxx | 252 |
1 files changed, 0 insertions, 252 deletions
diff --git a/src/input/RewindInputPlugin.cxx b/src/input/RewindInputPlugin.cxx deleted file mode 100644 index e11f56631..000000000 --- a/src/input/RewindInputPlugin.cxx +++ /dev/null @@ -1,252 +0,0 @@ -/* - * 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 "config.h" -#include "RewindInputPlugin.hxx" -#include "InputStream.hxx" -#include "InputPlugin.hxx" -#include "tag/Tag.hxx" - -#include <assert.h> -#include <string.h> -#include <stdio.h> - -extern const InputPlugin rewind_input_plugin; - -struct RewindInputStream { - InputStream base; - - InputStream *input; - - /** - * The read position within the buffer. Undefined as long as - * ReadingFromBuffer() returns false. - */ - size_t head; - - /** - * The write/append position within the buffer. - */ - size_t tail; - - /** - * The size of this buffer is the maximum number of bytes - * which can be rewinded cheaply without passing the "seek" - * call to CURL. - * - * The origin of this buffer is always the beginning of the - * stream (offset 0). - */ - char buffer[64 * 1024]; - - RewindInputStream(InputStream *_input) - :base(rewind_input_plugin, _input->uri.c_str(), - _input->mutex, _input->cond), - input(_input), tail(0) { - } - - ~RewindInputStream() { - input->Close(); - } - - /** - * Are we currently reading from the buffer, and does the - * buffer contain more data for the next read operation? - */ - bool ReadingFromBuffer() const { - return tail > 0 && base.offset < input->offset; - } - - /** - * Copy public attributes from the underlying input stream to the - * "rewind" input stream. This function is called when a method of - * the underlying stream has returned, which may have modified these - * attributes. - */ - void CopyAttributes() { - InputStream *dest = &base; - const InputStream *src = input; - - assert(dest != src); - - bool dest_ready = dest->ready; - - dest->ready = src->ready; - dest->seekable = src->seekable; - dest->size = src->size; - dest->offset = src->offset; - - if (!dest_ready && src->ready) - dest->mime = src->mime; - } -}; - -static void -input_rewind_close(InputStream *is) -{ - RewindInputStream *r = (RewindInputStream *)is; - - delete r; -} - -static bool -input_rewind_check(InputStream *is, Error &error) -{ - RewindInputStream *r = (RewindInputStream *)is; - - return r->input->Check(error); -} - -static void -input_rewind_update(InputStream *is) -{ - RewindInputStream *r = (RewindInputStream *)is; - - if (!r->ReadingFromBuffer()) - r->CopyAttributes(); -} - -static Tag * -input_rewind_tag(InputStream *is) -{ - RewindInputStream *r = (RewindInputStream *)is; - - return r->input->ReadTag(); -} - -static bool -input_rewind_available(InputStream *is) -{ - RewindInputStream *r = (RewindInputStream *)is; - - return r->input->IsAvailable(); -} - -static size_t -input_rewind_read(InputStream *is, void *ptr, size_t size, - Error &error) -{ - RewindInputStream *r = (RewindInputStream *)is; - - if (r->ReadingFromBuffer()) { - /* buffered read */ - - assert(r->head == (size_t)is->offset); - assert(r->tail == (size_t)r->input->offset); - - if (size > r->tail - r->head) - size = r->tail - r->head; - - memcpy(ptr, r->buffer + r->head, size); - r->head += size; - is->offset += size; - - return size; - } else { - /* pass method call to underlying stream */ - - size_t nbytes = r->input->Read(ptr, size, error); - - if (r->input->offset > (InputPlugin::offset_type)sizeof(r->buffer)) - /* disable buffering */ - r->tail = 0; - else if (r->tail == (size_t)is->offset) { - /* append to buffer */ - - memcpy(r->buffer + r->tail, ptr, nbytes); - r->tail += nbytes; - - assert(r->tail == (size_t)r->input->offset); - } - - r->CopyAttributes(); - - return nbytes; - } -} - -static bool -input_rewind_eof(InputStream *is) -{ - RewindInputStream *r = (RewindInputStream *)is; - - return !r->ReadingFromBuffer() && r->input->IsEOF(); -} - -static bool -input_rewind_seek(InputStream *is, InputPlugin::offset_type offset, - int whence, - Error &error) -{ - RewindInputStream *r = (RewindInputStream *)is; - - assert(is->ready); - - if (whence == SEEK_SET && r->tail > 0 && - offset <= (InputPlugin::offset_type)r->tail) { - /* buffered seek */ - - assert(!r->ReadingFromBuffer() || - r->head == (size_t)is->offset); - assert(r->tail == (size_t)r->input->offset); - - r->head = (size_t)offset; - is->offset = offset; - - return true; - } else { - bool success = r->input->Seek(offset, whence, error); - r->CopyAttributes(); - - /* disable the buffer, because r->input has left the - buffered range now */ - r->tail = 0; - - return success; - } -} - -const InputPlugin rewind_input_plugin = { - nullptr, - nullptr, - nullptr, - nullptr, - input_rewind_close, - input_rewind_check, - input_rewind_update, - input_rewind_tag, - input_rewind_available, - input_rewind_read, - input_rewind_eof, - input_rewind_seek, -}; - -InputStream * -input_rewind_open(InputStream *is) -{ - assert(is != nullptr); - assert(is->offset == 0); - - if (is->seekable) - /* seekable resources don't need this plugin */ - return is; - - RewindInputStream *c = new RewindInputStream(is); - return &c->base; -} |