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/*
* DEBUG: section 19 Store Memory Primitives
* AUTHOR: Robert Collins
*
* SQUID Web Proxy Cache http://www.squid-cache.org/
* ----------------------------------------------------------
*
* Squid is the result of efforts by numerous individuals from
* the Internet community; see the CONTRIBUTORS file for full
* details. Many organizations have provided support for Squid's
* development; see the SPONSORS file for full details. Squid is
* Copyrighted (C) 2001 by the Regents of the University of
* California; see the COPYRIGHT file for full details. Squid
* incorporates software developed and/or copyrighted by other
* sources; see the CREDITS file for full details.
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
*
*/
#include "squid.h"
#include "comm/Connection.h"
#include "Generic.h"
#include "globals.h"
#include "HttpReply.h"
#include "HttpRequest.h"
#include "MemBuf.h"
#include "MemObject.h"
#include "profiler/Profiler.h"
#include "SquidConfig.h"
#include "Store.h"
#include "StoreClient.h"
#if USE_DELAY_POOLS
#include "DelayPools.h"
#endif
/* TODO: make this global or private */
#if URL_CHECKSUM_DEBUG
static unsigned int url_checksum(const char *url);
unsigned int
url_checksum(const char *url)
{
unsigned int ck;
SquidMD5_CTX M;
static unsigned char digest[16];
SquidMD5Init(&M);
SquidMD5Update(&M, (unsigned char *) url, strlen(url));
SquidMD5Final(digest, &M);
memcpy(&ck, digest, sizeof(ck));
return ck;
}
#endif
RemovalPolicy * mem_policy = NULL;
size_t
MemObject::inUseCount()
{
return Pool().inUseCount();
}
void
MemObject::resetUrls(char const *aUrl, char const *aLog_url)
{
safe_free(url);
safe_free(log_url); /* XXX account log_url */
log_url = xstrdup(aLog_url);
url = xstrdup(aUrl);
}
MemObject::MemObject(char const *aUrl, char const *aLog_url)
{
debugs(20, 3, HERE << "new MemObject " << this);
_reply = new HttpReply;
HTTPMSGLOCK(_reply);
url = xstrdup(aUrl);
#if URL_CHECKSUM_DEBUG
chksum = url_checksum(url);
#endif
log_url = xstrdup(aLog_url);
object_sz = -1;
/* XXX account log_url */
swapout.decision = SwapOut::swNeedsCheck;
}
MemObject::~MemObject()
{
debugs(20, 3, HERE << "del MemObject " << this);
const Ctx ctx = ctx_enter(url);
#if URL_CHECKSUM_DEBUG
assert(chksum == url_checksum(url));
#endif
if (!shutting_down)
assert(swapout.sio == NULL);
data_hdr.freeContent();
#if 0
/*
* There is no way to abort FD-less clients, so they might
* still have mem->clients set.
*/
assert(clients.head == NULL);
#endif
HTTPMSGUNLOCK(_reply);
HTTPMSGUNLOCK(request);
ctx_exit(ctx); /* must exit before we free mem->url */
safe_free(url);
safe_free(log_url); /* XXX account log_url */
safe_free(vary_headers);
}
void
MemObject::unlinkRequest()
{
HTTPMSGUNLOCK(request);
}
void
MemObject::write ( StoreIOBuffer writeBuffer, STMCB *callback, void *callbackData)
{
PROF_start(MemObject_write);
debugs(19, 6, "memWrite: offset " << writeBuffer.offset << " len " << writeBuffer.length);
/* the offset is into the content, not the headers */
writeBuffer.offset += (_reply ? _reply->hdr_sz : 0);
/* We don't separate out mime headers yet, so ensure that the first
* write is at offset 0 - where they start
*/
assert (data_hdr.endOffset() || writeBuffer.offset == 0);
assert (data_hdr.write (writeBuffer));
callback (callbackData, writeBuffer);
PROF_stop(MemObject_write);
}
void
MemObject::dump() const
{
data_hdr.dump();
#if 0
/* do we want this one? */
debugs(20, DBG_IMPORTANT, "MemObject->data.origin_offset: " << (data_hdr.head ? data_hdr.head->nodeBuffer.offset : 0));
#endif
debugs(20, DBG_IMPORTANT, "MemObject->start_ping: " << start_ping.tv_sec << "."<< std::setfill('0') << std::setw(6) << start_ping.tv_usec);
debugs(20, DBG_IMPORTANT, "MemObject->inmem_hi: " << data_hdr.endOffset());
debugs(20, DBG_IMPORTANT, "MemObject->inmem_lo: " << inmem_lo);
debugs(20, DBG_IMPORTANT, "MemObject->nclients: " << nclients);
debugs(20, DBG_IMPORTANT, "MemObject->reply: " << _reply);
debugs(20, DBG_IMPORTANT, "MemObject->request: " << request);
debugs(20, DBG_IMPORTANT, "MemObject->log_url: " << checkNullString(log_url));
}
HttpReply const *
MemObject::getReply() const
{
return _reply;
}
void
MemObject::replaceHttpReply(HttpReply *newrep)
{
HTTPMSGUNLOCK(_reply);
_reply = newrep;
HTTPMSGLOCK(_reply);
}
struct LowestMemReader : public unary_function<store_client, void> {
LowestMemReader(int64_t seed):current(seed) {}
void operator() (store_client const &x) {
if (x.memReaderHasLowerOffset(current))
current = x.copyInto.offset;
}
int64_t current;
};
struct StoreClientStats : public unary_function<store_client, void> {
StoreClientStats(MemBuf *anEntry):where(anEntry),index(0) {}
void operator()(store_client const &x) {
x.dumpStats(where, index);
++index;
}
MemBuf *where;
size_t index;
};
void
MemObject::stat(MemBuf * mb) const
{
mb->Printf("\t%s %s\n",
RequestMethodStr(method), log_url);
if (vary_headers)
mb->Printf("\tvary_headers: %s\n", vary_headers);
mb->Printf("\tinmem_lo: %" PRId64 "\n", inmem_lo);
mb->Printf("\tinmem_hi: %" PRId64 "\n", data_hdr.endOffset());
mb->Printf("\tswapout: %" PRId64 " bytes queued\n",
swapout.queue_offset);
if (swapout.sio.getRaw())
mb->Printf("\tswapout: %" PRId64 " bytes written\n",
(int64_t) swapout.sio->offset());
StoreClientStats statsVisitor(mb);
for_each<StoreClientStats>(clients, statsVisitor);
}
int64_t
MemObject::endOffset () const
{
return data_hdr.endOffset();
}
void
MemObject::markEndOfReplyHeaders()
{
const int hdr_sz = endOffset();
assert(hdr_sz >= 0);
assert(_reply);
_reply->hdr_sz = hdr_sz;
}
int64_t
MemObject::size() const
{
if (object_sz < 0)
return endOffset();
return object_sz;
}
int64_t
MemObject::expectedReplySize() const
{
debugs(20, 7, HERE << "object_sz: " << object_sz);
if (object_sz >= 0) // complete() has been called; we know the exact answer
return object_sz;
if (_reply) {
const int64_t clen = _reply->bodySize(method);
debugs(20, 7, HERE << "clen: " << clen);
if (clen >= 0 && _reply->hdr_sz > 0) // yuck: HttpMsg sets hdr_sz to 0
return clen + _reply->hdr_sz;
}
return -1; // not enough information to predict
}
void
MemObject::reset()
{
assert(swapout.sio == NULL);
data_hdr.freeContent();
inmem_lo = 0;
/* Should we check for clients? */
}
int64_t
MemObject::lowestMemReaderOffset() const
{
LowestMemReader lowest (endOffset() + 1);
for_each <LowestMemReader>(clients, lowest);
return lowest.current;
}
/* XXX: This is wrong. It breaks *badly* on range combining */
bool
MemObject::readAheadPolicyCanRead() const
{
return endOffset() - getReply()->hdr_sz < lowestMemReaderOffset() + Config.readAheadGap;
}
void
MemObject::addClient(store_client *aClient)
{
++nclients;
dlinkAdd(aClient, &aClient->node, &clients);
}
#if URL_CHECKSUM_DEBUG
void
MemObject::checkUrlChecksum () const
{
assert(chksum == url_checksum(url));
}
#endif
/*
* How much of the object data is on the disk?
*/
int64_t
MemObject::objectBytesOnDisk() const
{
/*
* NOTE: storeOffset() represents the disk file size,
* not the amount of object data on disk.
*
* If we don't have at least 'swap_hdr_sz' bytes
* then none of the object data is on disk.
*
* This should still be safe if swap_hdr_sz == 0,
* meaning we haven't even opened the swapout file
* yet.
*/
if (swapout.sio.getRaw() == NULL)
return 0;
int64_t nwritten = swapout.sio->offset();
if (nwritten <= (int64_t)swap_hdr_sz)
return 0;
return (nwritten - swap_hdr_sz);
}
int64_t
MemObject::policyLowestOffsetToKeep(bool swap) const
{
/*
* Careful. lowest_offset can be greater than endOffset(), such
* as in the case of a range request.
*/
int64_t lowest_offset = lowestMemReaderOffset();
if (endOffset() < lowest_offset ||
endOffset() - inmem_lo > (int64_t)Config.Store.maxInMemObjSize ||
(swap && !Config.onoff.memory_cache_first))
return lowest_offset;
return inmem_lo;
}
void
MemObject::trimSwappable()
{
int64_t new_mem_lo = policyLowestOffsetToKeep(1);
/*
* We should only free up to what we know has been written
* to disk, not what has been queued for writing. Otherwise
* there will be a chunk of the data which is not in memory
* and is not yet on disk.
* The -1 makes sure the page isn't freed until storeSwapOut has
* walked to the next page.
*/
int64_t on_disk;
if ((on_disk = objectBytesOnDisk()) - 1 < new_mem_lo)
new_mem_lo = on_disk - 1;
if (new_mem_lo == -1)
new_mem_lo = 0; /* the above might become -1 */
data_hdr.freeDataUpto(new_mem_lo);
inmem_lo = new_mem_lo;
}
void
MemObject::trimUnSwappable()
{
int64_t new_mem_lo = policyLowestOffsetToKeep(0);
assert (new_mem_lo > 0);
data_hdr.freeDataUpto(new_mem_lo);
inmem_lo = new_mem_lo;
}
bool
MemObject::isContiguous() const
{
bool result = data_hdr.hasContigousContentRange (Range<int64_t>(inmem_lo, endOffset()));
/* XXX : make this higher level */
debugs (19, result ? 4 :3, "MemObject::isContiguous: Returning " << (result ? "true" : "false"));
return result;
}
int
MemObject::mostBytesWanted(int max, bool ignoreDelayPools) const
{
#if USE_DELAY_POOLS
if (!ignoreDelayPools) {
/* identify delay id with largest allowance */
DelayId largestAllowance = mostBytesAllowed ();
return largestAllowance.bytesWanted(0, max);
}
#endif
return max;
}
void
MemObject::setNoDelay(bool const newValue)
{
#if USE_DELAY_POOLS
for (dlink_node *node = clients.head; node; node = node->next) {
store_client *sc = (store_client *) node->data;
sc->delayId.setNoDelay(newValue);
}
#endif
}
void
MemObject::delayRead(DeferredRead const &aRead)
{
deferredReads.delayRead(aRead);
}
void
MemObject::kickReads()
{
deferredReads.kickReads(-1);
}
#if USE_DELAY_POOLS
DelayId
MemObject::mostBytesAllowed() const
{
int j;
int jmax = -1;
DelayId result;
for (dlink_node *node = clients.head; node; node = node->next) {
store_client *sc = (store_client *) node->data;
#if 0
/* This test is invalid because the client may be writing data
* and thus will want data immediately.
* If we include the test, there is a race condition when too much
* data is read - if all sc's are writing when a read is scheduled.
* XXX: fixme.
*/
if (!sc->callbackPending())
/* not waiting for more data */
continue;
#endif
j = sc->delayId.bytesWanted(0, sc->copyInto.length);
if (j > jmax) {
jmax = j;
result = sc->delayId;
}
}
return result;
}
#endif
int64_t
MemObject::availableForSwapOut() const
{
return endOffset() - swapout.queue_offset;
}
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