Files
SingularityViewer/indra/llmessage/aicurlperhost.cpp
Aleric Inglewood d26241c0f2 Move extract_canonical_hostname to AIPerHostRequestQueue::extract_canonical_hostname.
This to make it available to the texture fetcher.
2013-04-08 06:41:07 +02:00

244 lines
8.1 KiB
C++

/**
* @file aiperhost.cpp
* @brief Implementation of AIPerHostRequestQueue
*
* Copyright (c) 2012, 2013, Aleric Inglewood.
*
* 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, see <http://www.gnu.org/licenses/>.
*
* There are special exceptions to the terms and conditions of the GPL as
* it is applied to this Source Code. View the full text of the exception
* in the file doc/FLOSS-exception.txt in this software distribution.
*
* CHANGELOG
* and additional copyright holders.
*
* 04/11/2012
* Initial version, written by Aleric Inglewood @ SL
*
* 06/04/2013
* Renamed AICurlPrivate::PerHostRequestQueue[Ptr] to AIPerHostRequestQueue[Ptr]
* to allow public access.
*/
#include "sys.h"
#include "aicurlperhost.h"
#include "aicurlthread.h"
AIPerHostRequestQueue::threadsafe_instance_map_type AIPerHostRequestQueue::sInstanceMap;
LLAtomicS32 AIPerHostRequestQueue::sTotalQueued;
#undef AICurlPrivate
namespace AICurlPrivate {
U32 curl_concurrent_connections_per_host;
// Friend functions of RefCountedThreadSafePerHostRequestQueue
void intrusive_ptr_add_ref(RefCountedThreadSafePerHostRequestQueue* per_host)
{
per_host->mReferenceCount++;
}
void intrusive_ptr_release(RefCountedThreadSafePerHostRequestQueue* per_host)
{
if (--per_host->mReferenceCount == 0)
{
delete per_host;
}
}
} // namespace AICurlPrivate
using namespace AICurlPrivate;
// url must be of the form
// (see http://www.ietf.org/rfc/rfc3986.txt Appendix A for definitions not given here):
//
// url = sheme ":" hier-part [ "?" query ] [ "#" fragment ]
// hier-part = "//" authority path-abempty
// authority = [ userinfo "@" ] host [ ":" port ]
// path-abempty = *( "/" segment )
//
// That is, a hier-part of the form '/ path-absolute', '/ path-rootless' or
// '/ path-empty' is NOT allowed here. This should be safe because we only
// call this function for curl access, any file access would use APR.
//
// However, as a special exception, this function allows:
//
// url = authority path-abempty
//
// without the 'sheme ":" "//"' parts.
//
// As follows from the ABNF (see RFC, Appendix A):
// - authority is either terminated by a '/' or by the end of the string because
// neither userinfo, host nor port may contain a '/'.
// - userinfo does not contain a '@', and if it exists, is always terminated by a '@'.
// - port does not contain a ':', and if it exists is always prepended by a ':'.
//
//static
std::string AIPerHostRequestQueue::extract_canonical_hostname(std::string const& url)
{
std::string::size_type pos;
std::string::size_type authority = 0; // Default if there is no sheme.
if ((pos = url.find("://")) != url.npos && pos < url.find('/')) authority = pos + 3; // Skip the "sheme://" if any, the second find is to avoid finding a "://" as part of path-abempty.
std::string::size_type host = authority; // Default if there is no userinfo.
if ((pos = url.find('@', authority)) != url.npos) host = pos + 1; // Skip the "userinfo@" if any.
authority = url.length() - 1; // Default last character of host if there is no path-abempty.
if ((pos = url.find('/', host)) != url.npos) authority = pos - 1; // Point to last character of host.
std::string::size_type len = url.find_last_not_of(":0123456789", authority) - host + 1; // Skip trailing ":port", if any.
std::string hostname(url, host, len);
#if APR_CHARSET_EBCDIC
#error Not implemented
#else
// Convert hostname to lowercase in a way that we compare two hostnames equal iff libcurl does.
for (std::string::iterator iter = hostname.begin(); iter != hostname.end(); ++iter)
{
int c = *iter;
if (c >= 'A' && c <= 'Z')
*iter = c + ('a' - 'A');
}
#endif
return hostname;
}
//static
AIPerHostRequestQueuePtr AIPerHostRequestQueue::instance(std::string const& hostname)
{
llassert(!hostname.empty());
instance_map_wat instance_map_w(sInstanceMap);
AIPerHostRequestQueue::iterator iter = instance_map_w->find(hostname);
if (iter == instance_map_w->end())
{
iter = instance_map_w->insert(instance_map_type::value_type(hostname, new RefCountedThreadSafePerHostRequestQueue)).first;
}
// Note: the creation of AIPerHostRequestQueuePtr MUST be protected by the lock on sInstanceMap (see release()).
return iter->second;
}
//static
void AIPerHostRequestQueue::release(AIPerHostRequestQueuePtr& instance)
{
if (instance->exactly_two_left()) // Being 'instance' and the one in sInstanceMap.
{
// The viewer can be have left main() we can't access the global sInstanceMap anymore.
if (LLApp::isStopped())
{
return;
}
instance_map_wat instance_map_w(sInstanceMap);
// It is possible that 'exactly_two_left' is not up to date anymore.
// Therefore, recheck the condition now that we have locked sInstanceMap.
if (!instance->exactly_two_left())
{
// Some other thread added this host in the meantime.
return;
}
// The reference in the map is the last one; that means there can't be any curl easy requests queued for this host.
llassert(PerHostRequestQueue_rat(*instance)->mQueuedRequests.empty());
// Find the host and erase it from the map.
iterator const end = instance_map_w->end();
for(iterator iter = instance_map_w->begin(); iter != end; ++iter)
{
if (instance == iter->second)
{
instance_map_w->erase(iter);
instance.reset();
return;
}
}
// We should always find the host.
llassert(false);
}
instance.reset();
}
bool AIPerHostRequestQueue::throttled() const
{
llassert(mAdded <= int(curl_concurrent_connections_per_host));
return mAdded == int(curl_concurrent_connections_per_host);
}
void AIPerHostRequestQueue::added_to_multi_handle(void)
{
llassert(mAdded < int(curl_concurrent_connections_per_host));
++mAdded;
}
void AIPerHostRequestQueue::removed_from_multi_handle(void)
{
--mAdded;
llassert(mAdded >= 0);
}
void AIPerHostRequestQueue::queue(AICurlEasyRequest const& easy_request)
{
mQueuedRequests.push_back(easy_request.get_ptr());
sTotalQueued++;
}
bool AIPerHostRequestQueue::cancel(AICurlEasyRequest const& easy_request)
{
queued_request_type::iterator const end = mQueuedRequests.end();
queued_request_type::iterator cur = std::find(mQueuedRequests.begin(), end, easy_request.get_ptr());
if (cur == end)
return false; // Not found.
// We can't use erase because that uses assignment to move elements,
// because it isn't thread-safe. Therefore, move the element that we found to
// the back with swap (could just swap with the end immediately, but I don't
// want to break the order in which requests where added). Swap is also not
// thread-safe, but OK here because it only touches the objects in the deque,
// and the deque is protected by the lock on the AIPerHostRequestQueue object.
queued_request_type::iterator prev = cur;
while (++cur != end)
{
prev->swap(*cur); // This is safe,
prev = cur;
}
mQueuedRequests.pop_back(); // if this is safe.
--sTotalQueued;
llassert(sTotalQueued >= 0);
return true;
}
void AIPerHostRequestQueue::add_queued_to(curlthread::MultiHandle* multi_handle)
{
if (!mQueuedRequests.empty())
{
multi_handle->add_easy_request(mQueuedRequests.front());
mQueuedRequests.pop_front();
--sTotalQueued;
llassert(sTotalQueued >= 0);
}
}
//static
void AIPerHostRequestQueue::purge(void)
{
instance_map_wat instance_map_w(sInstanceMap);
for (iterator host = instance_map_w->begin(); host != instance_map_w->end(); ++host)
{
Dout(dc::curl, "Purging queue of host \"" << host->first << "\".");
PerHostRequestQueue_wat per_host_w(*host->second);
size_t s = per_host_w->mQueuedRequests.size();
per_host_w->mQueuedRequests.clear();
sTotalQueued -= s;
llassert(sTotalQueued >= 0);
}
}