mpd/src/input/plugins/SmbclientInputPlugin.cxx
Max Kellermann 3a0d6d96c1 input/smbclient: wrap in MaybeBufferedInputStream
This enables the input buffer for remote files and caches file
contents in MPD.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/376
2019-04-23 14:08:27 +02:00

168 lines
3.7 KiB
C++

/*
* Copyright 2003-2018 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 "SmbclientInputPlugin.hxx"
#include "lib/smbclient/Init.hxx"
#include "lib/smbclient/Mutex.hxx"
#include "../InputStream.hxx"
#include "../InputPlugin.hxx"
#include "../MaybeBufferedInputStream.hxx"
#include "PluginUnavailable.hxx"
#include "system/Error.hxx"
#include "util/ASCII.hxx"
#include <libsmbclient.h>
class SmbclientInputStream final : public InputStream {
SMBCCTX *ctx;
int fd;
public:
SmbclientInputStream(const char *_uri,
Mutex &_mutex,
SMBCCTX *_ctx, int _fd, const struct stat &st)
:InputStream(_uri, _mutex),
ctx(_ctx), fd(_fd) {
seekable = true;
size = st.st_size;
SetReady();
}
~SmbclientInputStream() {
smbclient_mutex.lock();
smbc_close(fd);
smbc_free_context(ctx, 1);
smbclient_mutex.unlock();
}
/* virtual methods from InputStream */
bool IsEOF() noexcept override {
return offset >= size;
}
size_t Read(void *ptr, size_t size) override;
void Seek(offset_type offset) override;
};
/*
* InputPlugin methods
*
*/
static void
input_smbclient_init(EventLoop &, const ConfigBlock &)
{
try {
SmbclientInit();
} catch (...) {
std::throw_with_nested(PluginUnavailable("libsmbclient initialization failed"));
}
// TODO: create one global SMBCCTX here?
// TODO: evaluate ConfigBlock, call smbc_setOption*()
}
static InputStreamPtr
input_smbclient_open(const char *uri,
Mutex &mutex)
{
const std::lock_guard<Mutex> protect(smbclient_mutex);
SMBCCTX *ctx = smbc_new_context();
if (ctx == nullptr)
throw MakeErrno("smbc_new_context() failed");
SMBCCTX *ctx2 = smbc_init_context(ctx);
if (ctx2 == nullptr) {
int e = errno;
smbc_free_context(ctx, 1);
throw MakeErrno(e, "smbc_init_context() failed");
}
ctx = ctx2;
int fd = smbc_open(uri, O_RDONLY, 0);
if (fd < 0) {
int e = errno;
smbc_free_context(ctx, 1);
throw MakeErrno(e, "smbc_open() failed");
}
struct stat st;
if (smbc_fstat(fd, &st) < 0) {
int e = errno;
smbc_free_context(ctx, 1);
throw MakeErrno(e, "smbc_fstat() failed");
}
return std::make_unique<MaybeBufferedInputStream>
(std::make_unique<SmbclientInputStream>(uri, mutex,
ctx, fd, st));
}
size_t
SmbclientInputStream::Read(void *ptr, size_t read_size)
{
ssize_t nbytes;
{
const ScopeUnlock unlock(mutex);
const std::lock_guard<Mutex> lock(smbclient_mutex);
nbytes = smbc_read(fd, ptr, read_size);
}
if (nbytes < 0)
throw MakeErrno("smbc_read() failed");
offset += nbytes;
return nbytes;
}
void
SmbclientInputStream::Seek(offset_type new_offset)
{
off_t result;
{
const ScopeUnlock unlock(mutex);
const std::lock_guard<Mutex> lock(smbclient_mutex);
result = smbc_lseek(fd, new_offset, SEEK_SET);
}
if (result < 0)
throw MakeErrno("smbc_lseek() failed");
offset = result;
}
static constexpr const char *smbclient_prefixes[] = {
"smb://",
nullptr
};
const InputPlugin input_plugin_smbclient = {
"smbclient",
smbclient_prefixes,
input_smbclient_init,
nullptr,
input_smbclient_open,
};