Files
foobar2000-sdk/foobar2000/helpers/readers.cpp
2021-12-14 00:28:25 -07:00

384 lines
11 KiB
C++

#include "StdAfx.h"
#include "readers.h"
#include "fullFileBuffer.h"
#include "fileReadAhead.h"
#include <list>
t_size reader_membuffer_base::read(void * p_buffer, t_size p_bytes, abort_callback & p_abort) {
p_abort.check_e();
t_size max = get_buffer_size();
if (max < m_offset) uBugCheck();
max -= m_offset;
t_size delta = p_bytes;
if (delta > max) delta = max;
memcpy(p_buffer, (char*)get_buffer() + m_offset, delta);
m_offset += delta;
return delta;
}
void reader_membuffer_base::seek(t_filesize position, abort_callback & p_abort) {
p_abort.check_e();
t_filesize max = get_buffer_size();
if (position == filesize_invalid || position > max) throw exception_io_seek_out_of_range();
m_offset = (t_size)position;
}
file::ptr fullFileBuffer::open(const char * path, abort_callback & abort, file::ptr hint, t_filesize sizeMax) {
//mutexScope scope(hMutex, abort);
file::ptr f;
if (hint.is_valid()) f = hint;
else filesystem::g_open_read(f, path, abort);
if (sizeMax != filesize_invalid) {
t_filesize fs = f->get_size(abort);
if (fs > sizeMax) return f;
}
try {
service_ptr_t<reader_bigmem_mirror> r = new service_impl_t<reader_bigmem_mirror>();
r->init(f, abort);
f = r;
}
catch (std::bad_alloc) {}
return f;
}
#include <memory>
#include "rethrow.h"
#include <pfc/synchro.h>
#include <pfc/threads.h>
namespace {
struct dynInfoEntry_t {
file_info_impl m_info;
t_filesize m_offset;
};
struct readAheadInstance_t {
file::ptr m_file;
size_t m_readAhead, m_wakeUpThreschold;
pfc::array_t<uint8_t> m_buffer;
size_t m_bufferBegin, m_bufferEnd;
pfc::event m_canRead, m_canWrite;
pfc::mutex m_guard;
ThreadUtils::CRethrow m_error;
t_filesize m_seekto;
abort_callback_impl m_abort;
bool m_remote;
bool m_atEOF = false;
bool m_haveDynamicInfo;
std::list<dynInfoEntry_t> m_dynamicInfo;
};
typedef std::shared_ptr<readAheadInstance_t> readAheadInstanceRef;
static const t_filesize seek_reopen = (filesize_invalid-1);
class fileReadAhead : public file_readonly_t<file_dynamicinfo_v2> {
public:
readAheadInstanceRef m_instance;
~fileReadAhead() {
if ( m_instance ) {
auto & i = *m_instance;
pfc::mutexScope guard( i.m_guard );
i.m_abort.set();
i.m_canWrite.set_state(true);
}
}
void initialize( file::ptr chain, size_t readAhead, abort_callback & aborter ) {
m_stats = chain->get_stats( aborter );
if (!chain->get_content_type(m_contentType)) m_contentType = "";
m_canSeek = chain->can_seek();
m_position = chain->get_position( aborter );
auto i = std::make_shared<readAheadInstance_t>();;
i->m_file = chain;
i->m_remote = chain->is_remote();
i->m_readAhead = readAhead;
i->m_wakeUpThreschold = readAhead * 3 / 4;
i->m_buffer.set_size_discard( readAhead * 2 );
i->m_bufferBegin = 0; i->m_bufferEnd = 0;
i->m_canWrite.set_state(true);
i->m_seekto = filesize_invalid;
m_instance = i;
{
file_dynamicinfo::ptr dyn;
if (dyn &= chain) {
m_haveStaticInfo = dyn->get_static_info(m_staticInfo);
i->m_haveDynamicInfo = dyn->is_dynamic_info_enabled();
}
}
fb2k::splitTask( [i] {
#ifdef PFC_SET_THREAD_DESCRIPTION
PFC_SET_THREAD_DESCRIPTION("Fb2k Read-Ahead Thread");
#endif
worker(*i);
} );
}
t_size read(void * p_buffer,t_size p_bytes,abort_callback & p_abort) {
auto & i = * m_instance;
size_t done = 0;
bool initial = true;
while( done < p_bytes ) {
if ( !initial ) {
// Do not invoke waiting with common case read with lots of data in the buffer
pfc::event::g_twoEventWait( i.m_canRead.get_handle(), p_abort.get_abort_event(), -1);
}
p_abort.check();
pfc::mutexScope guard ( i.m_guard );
size_t got = i.m_bufferEnd - i.m_bufferBegin;
if (got == 0) {
i.m_error.rethrow();
if ( initial && ! i.m_atEOF ) {
initial = false; continue; // proceed to wait for more data
}
break; // EOF
}
size_t delta = pfc::min_t<size_t>( p_bytes - done, got );
const bool wakeUpBefore = got < i.m_wakeUpThreschold;
auto bufptr = i.m_buffer.get_ptr();
if ( p_buffer != nullptr ) memcpy( (uint8_t*) p_buffer + done, bufptr + i.m_bufferBegin, delta );
done += delta;
i.m_bufferBegin += delta;
got -= delta;
m_position += delta;
if (!i.m_error.didFail() && !i.m_atEOF) {
if ( got == 0 ) i.m_canRead.set_state( false );
const bool wakeUpNow = got < i.m_wakeUpThreschold;
// Only set the event when *crossing* the boundary
// we will get a lot of wakeUpNow when nearing EOF
if ( wakeUpNow && ! wakeUpBefore ) i.m_canWrite.set_state( true );
}
initial = false;
if ( i.m_atEOF ) break; // go no further
}
// FB2K_console_formatter() << "ReadAhead read: " << p_bytes << " => " << done;
return done;
}
t_filesize get_size(abort_callback & p_abort) {
p_abort.check();
return m_stats.m_size;
}
t_filesize get_position(abort_callback & p_abort) {
p_abort.check();
return m_position;
}
void seek(t_filesize p_position,abort_callback & p_abort) {
p_abort.check();
if (!m_canSeek) throw exception_io_object_not_seekable();
if ( m_stats.m_size != filesize_invalid && p_position > m_stats.m_size ) throw exception_io_seek_out_of_range();
auto posNow = get_position(p_abort);
if ( p_position >= posNow && p_position < posNow + m_instance->m_readAhead ) {
// FB2K_console_formatter() << "ReadAhead skip: " << posNow << " => " << p_position;
auto toSkip = p_position - posNow;
if ( toSkip > 0 ) read(nullptr, (size_t) toSkip, p_abort);
return;
}
// FB2K_console_formatter() << "ReadAhead seek: " << posNow << " => " << p_position;
seekInternal( p_position );
}
bool can_seek() {
return m_canSeek;
}
bool get_content_type(pfc::string_base & p_out) {
if (m_contentType.length() == 0) return false;
p_out = m_contentType; return true;
}
t_filestats get_stats( abort_callback & p_abort ) {
p_abort.check();
return m_stats;
}
t_filetimestamp get_timestamp(abort_callback & p_abort) {
p_abort.check();
return m_stats.m_timestamp;
}
bool is_remote() {
return m_instance->m_remote;
}
void reopen( abort_callback & p_abort ) {
if ( get_position( p_abort ) == 0 ) return;
seekInternal( seek_reopen );
}
bool get_static_info(class file_info & p_out) {
if ( ! m_haveStaticInfo ) return false;
mergeInfo(p_out, m_staticInfo);
return true;
}
bool is_dynamic_info_enabled() {
return m_instance->m_haveDynamicInfo;
}
static void mergeInfo( file_info & out, const file_info & in ) {
out.copy_meta(in);
out.overwrite_info(in);
}
bool get_dynamic_info_v2(class file_info & out, t_filesize & outOffset) {
auto & i = * m_instance;
if ( ! i.m_haveDynamicInfo ) return false;
insync( i.m_guard );
auto ptr = i.m_dynamicInfo.begin();
for ( ;; ) {
if ( ptr == i.m_dynamicInfo.end() ) break;
if ( ptr->m_offset > m_position ) break;
++ ptr;
}
if ( ptr == i.m_dynamicInfo.begin() ) return false;
auto iter = ptr; --iter;
mergeInfo(out, iter->m_info);
outOffset = iter->m_offset;
i.m_dynamicInfo.erase( i.m_dynamicInfo.begin(), ptr );
return true;
}
private:
void seekInternal( t_filesize p_position ) {
auto & i = * m_instance;
insync( i.m_guard );
i.m_error.rethrow();
i.m_bufferBegin = i.m_bufferEnd = 0;
i.m_canWrite.set_state(true);
i.m_seekto = p_position;
i.m_atEOF = false;
i.m_canRead.set_state(false);
m_position = ( p_position == seek_reopen ) ? 0 : p_position;
}
static void worker( readAheadInstance_t & i ) {
ThreadUtils::CRethrow err;
err.exec( [&i] {
bool atEOF = false;
uint8_t* bufptr = i.m_buffer.get_ptr();
const size_t readAtOnceLimit = i.m_remote ? 256 : 4*1024;
for ( ;; ) {
i.m_canWrite.wait_for(-1);
size_t readHowMuch = 0, readOffset = 0;
{
pfc::mutexScope guard(i.m_guard);
i.m_abort.check();
if ( i.m_seekto != filesize_invalid ) {
if ( i.m_seekto == seek_reopen ) {
i.m_file->reopen( i.m_abort );
} else {
i.m_file->seek( i.m_seekto, i.m_abort );
}
i.m_seekto = filesize_invalid;
atEOF = false;
}
size_t got = i.m_bufferEnd - i.m_bufferBegin;
if ( i.m_bufferBegin >= i.m_readAhead ) {
memmove( bufptr, bufptr + i.m_bufferBegin, got );
i.m_bufferBegin = 0;
i.m_bufferEnd = got;
}
if ( got < i.m_readAhead ) {
readHowMuch = i.m_readAhead - got;
readOffset = i.m_bufferEnd;
}
}
if ( readHowMuch > readAtOnceLimit ) {
readHowMuch = readAtOnceLimit;
}
bool dynInfoGot = false;
dynInfoEntry_t dynInfo;
if ( readHowMuch > 0 ) {
readHowMuch = i.m_file->read( bufptr + readOffset, readHowMuch, i.m_abort );
if ( readHowMuch == 0 ) atEOF = true;
if ( i.m_haveDynamicInfo ) {
file_dynamicinfo::ptr dyn;
if ( dyn &= i.m_file ) {
file_dynamicinfo_v2::ptr dyn2;
if ( dyn2 &= dyn ) {
dynInfoGot = dyn2->get_dynamic_info_v2(dynInfo.m_info, dynInfo.m_offset);
} else {
dynInfoGot = dyn->get_dynamic_info( dynInfo.m_info );
if (dynInfoGot) {
dynInfo.m_offset = dyn->get_position( i.m_abort );
}
}
}
}
}
{
pfc::mutexScope guard( i.m_guard );
i.m_abort.check();
if ( i.m_seekto != filesize_invalid ) {
// Seek request happened while we were reading - discard and continue
continue;
}
i.m_atEOF = atEOF;
i.m_canRead.set_state( true );
i.m_bufferEnd += readHowMuch;
size_t got = i.m_bufferEnd - i.m_bufferBegin;
if ( atEOF || got >= i.m_readAhead ) i.m_canWrite.set_state(false);
if ( dynInfoGot ) {
i.m_dynamicInfo.push_back( std::move(dynInfo) );
}
}
}
} );
if ( err.didFail( ) ) {
pfc::mutexScope guard( i.m_guard );
i.m_error = err;
i.m_canRead.set_state(true);
}
}
bool m_canSeek;
t_filestats m_stats;
pfc::string8 m_contentType;
t_filesize m_position;
bool m_haveStaticInfo;
file_info_impl m_staticInfo;
};
}
file::ptr fileCreateReadAhead(file::ptr chain, size_t readAheadBytes, abort_callback & aborter ) {
auto obj = fb2k::service_new<fileReadAhead>();
obj->initialize( chain, readAheadBytes, aborter );
return obj;
}