pagepool.cc

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	// cache size here!!
	return 0;
}

int ClientPagePool::set_mtime(const char *name, double mt)
{
	ClientPage *pg = (ClientPage *)get_page(name);
	if (pg == NULL) 
		return -1;
	pg->mtime() = mt;
	return 0;
}

int ClientPagePool::get_mtime(const char *name, double& mt)
{
	ClientPage *pg = (ClientPage *)get_page(name);
	if (pg == NULL) 
		return -1;
	mt = pg->mtime();
	return 0;
}

int ClientPagePool::set_etime(const char *name, double et)
{
	ClientPage *pg = (ClientPage *)get_page(name);
	if (pg == NULL) 
		return -1;
	pg->etime() = et;
	return 0;
}

int ClientPagePool::get_etime(const char *name, double& et)
{
	ClientPage *pg = (ClientPage *)get_page(name);
	if (pg == NULL) 
		return -1;
	et = pg->etime();
	return 0;
}

int ClientPagePool::get_size(const char *name, int& size) 
{
	ClientPage *pg = (ClientPage *)get_page(name);
	if (pg == NULL) 
		return -1;
	size = pg->size();
	return 0;
}

int ClientPagePool::get_age(const char *name, double& age) 
{
	ClientPage *pg = (ClientPage *)get_page(name);
	if (pg == NULL) 
		return -1;
	age = pg->age();
	return 0;
}

void ClientPagePool::invalidate_server(int sid)
{
	Tcl_HashEntry *he;
	Tcl_HashSearch hs;
	ClientPage *pg;
	int i;

	for (i = 0, he = Tcl_FirstHashEntry(namemap_, &hs);
	     he != NULL;
	     he = Tcl_NextHashEntry(&hs), i++) {
		pg = (ClientPage *) Tcl_GetHashValue(he);
		if (pg->server()->id() == sid)
			pg->server_down();
	}
}


// Proxy traces. Request file format:
//
// [<time> <clientID> <serverID> <URL_ID>]
// i <Duration> <Number_of_unique_URLs>
//
// <time> is guaranteed to start from 0. It needs to be adjusted
//
// Page file format (sorted by access counts)
// 
// <serverID> <URL_ID> <PageSize> <AccessCount>

static class ProxyTracePagePoolClass : public TclClass {
public:
        ProxyTracePagePoolClass() : TclClass("PagePool/ProxyTrace") {}
        TclObject* create(int, const char*const*) {
		return (new ProxyTracePagePool());
	}
} class_ProxyTracepagepool_agent;

ProxyTracePagePool::ProxyTracePagePool() : 
	rvDyn_(NULL), rvStatic_(NULL), br_(0), 
	size_(NULL), reqfile_(NULL), req_(NULL), lastseq_(0)
{
}

ProxyTracePagePool::~ProxyTracePagePool()
{
	if (size_ != NULL) 
		delete []size_;
	if (reqfile_ != NULL) 
		fclose(reqfile_);
	if (req_ != NULL) {
		Tcl_DeleteHashTable(req_);
		delete req_;
	}
}

int ProxyTracePagePool::init_req(const char *fn) 
{
	reqfile_ = fopen(fn, "r");
	if (reqfile_ == NULL) {
		fprintf(stderr, 
		  "ProxyTracePagePool: couldn't open trace file %s\n", fn);
		return TCL_ERROR;
	}

	// Discover information about the trace, e.g., number of pages,
	// start time, end time, etc. They should be available at the 
	// first line of the trace file.
	return find_info();
}

int ProxyTracePagePool::find_info()
{
	// Read the last line of the file
	fseek(reqfile_, -128, SEEK_END);
	char buf[129];
	if (fread(buf, 1, 128, reqfile_) != 128) {
		fprintf(stderr,
			"ProxyTracePagePool: cannot read file information\n");
		return TCL_ERROR;
	}
	int i;
	// ignore the last RETURN
	buf[128] = 0;
	if (buf[127] == '\n')
		buf[127] = 0; 
	for (i = 127; i >= 0; i--)
		if (buf[i] == '\n') {
			i++; 
			break;
		}
	if (buf[i] != 'i') {
		fprintf(stderr, 
	"ProxyTracePagePool: trace file doesn't contain statistics.\n");
		abort();
	}
	double len;
	sscanf(buf+i+1, "%lf %u", &len, &num_pages_);
	duration_ = (int)ceil(len);
#if 0
	printf("ProxyTracePagePool: duration %d pages %u\n",
	       duration_, num_pages_);
#endif
	rewind(reqfile_);
	return TCL_OK;
}

// Load page size info. Assuming request stream has already been loaded
int ProxyTracePagePool::init_page(const char *fn)
{
	FILE *fp = fopen(fn, "r");
	if (fp == NULL) {
		fprintf(stderr, 
		  "ProxyTracePagePool: couldn't open trace file %s\n", fn);
		return TCL_ERROR;
	}
	if (size_ != NULL) 
		delete []size_;
	int* p = new int[num_pages_];
	size_ = p;
	for (int i = 0; i < num_pages_; i++, p++)
		fscanf(fp, "%*d %*d %d %*u\n", p);
	fclose(fp);
	return TCL_OK;
}

ProxyTracePagePool::ClientRequest* ProxyTracePagePool::load_req(int cid)
{
	// Find out which client we are seeking
	Tcl_HashEntry *he;
	ClientRequest *p;
	int dummy; 
	
	if ((he = Tcl_FindHashEntry(req_, (const char*)cid)) == NULL) {
		// New entry
		p = new ClientRequest();
		p->seq_ = lastseq_++;
		he = Tcl_CreateHashEntry(req_, (const char*)cid, &dummy);
		Tcl_SetHashValue(he, (const char*)p);
		// Search from the beginning of file for this new client
		fseek(reqfile_, 0, SEEK_SET);
	} else {
		p = (ClientRequest*)Tcl_GetHashValue(he);
		if (p->nrt_ == -1)
			// No more requests for this client
			return p;
		// Clear EOF status
		fseek(reqfile_, p->fpos_, SEEK_SET);
	}

	// Looking for the next available request for this client
	double nrt;
	int ncid = -1, nurl;
	char buf[256];
	while (fgets(buf, 256, reqfile_)) {
		if (isalpha(buf[0])) {
			// Last line, break;
			ncid = -1;
			break;
		}
		sscanf(buf, "%lf %d %*d %d\n", &nrt, &ncid, &nurl);
		if ((ncid % nclient_) == p->seq_)
			break;
	}
	if ((ncid % nclient_) != p->seq_)
		// Didn't find the next request for this client
		p->nrt_ = -1;
	else {
		p->nrt_ = nrt, p->nurl_ = nurl;
		p->nrt_ += start_time_;
	}
	p->fpos_ = ftell(reqfile_);
	return p;
}

// Provide a tcl interface compatible with MathPagePool
int ProxyTracePagePool::command(int argc, const char*const* argv)
{
	Tcl& tcl = Tcl::instance();

	if (argc == 2) {
		if (strcmp(argv[1], "get-poolsize") == 0) { 
			tcl.resultf("%u", num_pages_);
			return TCL_OK;
		} else if (strcmp(argv[1], "get-start-time") == 0) {
			tcl.resultf("%.17g", start_time_);
			return TCL_OK;
		} else if (strcmp(argv[1], "get-duration") == 0) {
			tcl.resultf("%d", duration_);
			return TCL_OK;
		} else if (strcmp(argv[1], "bimodal-ratio") == 0) {
			tcl.resultf("%g", br_ / 10);
			return TCL_OK;
		}
	} else if (argc == 3) {
		if (strcmp(argv[1], "set-client-num") == 0) {
			// Set the number of clients it'll access
			// Cannot be changed once set
			if (req_ != NULL)
				return TCL_ERROR;
			int num = atoi(argv[2]);
			req_ = new Tcl_HashTable;
			Tcl_InitHashTable(req_, TCL_ONE_WORD_KEYS);
			nclient_ = num;
			return TCL_OK;
		} else if (strcmp(argv[1], "gen-request") == 0) {
			// Use client id to get a corresponding request
			int id = atoi(argv[2]);
			ClientRequest *p = load_req(id);
			if ((p->nrt_ >= 0) && 
			    (p->nrt_ < Scheduler::instance().clock())) {
				// XXX Do NOT treat this as an error, also
				// do NOT disable further requests from this 
				// client.
				fprintf(stderr,
					"%.17g: Wrong request time %g.\n",
					Scheduler::instance().clock(),
					p->nrt_);
				// XXX If it's a little bit older than current 
				// time, let it be a little bit later than now
				p->nrt_ = Scheduler::instance().clock()+0.001;
			}
			tcl.resultf("%lf %d", 
				    p->nrt_ - Scheduler::instance().clock(), 
				    p->nurl_);
			return TCL_OK;
		} else if (strcmp(argv[1], "gen-size") == 0) {
			int id = atoi(argv[2]);
			if ((id < 0) || (id > num_pages_)) {
				tcl.result("PagePool: id out of range.\n");
				return TCL_ERROR;
			}
			tcl.resultf("%d", size_[id]);
			return TCL_OK;
		} else if (strcmp(argv[1], "set-start-time") == 0) {
			start_time_ = strtod(argv[2], NULL);
			return TCL_OK;
		} else if (strcmp(argv[1], "bimodal-ratio") == 0) {
			// XXX Codes in Http/Server::gen-page{} also depends
			// on this dyn/static page algorithm. If this is 
			// changed, that instproc must be changed too.
			//
			// percentage of dynamic pages. E.g., 
			// if this ratio is 5, then page 0-4 is 
			// dynamic, and page 4-99 is static, and so on.
			double ratio = strtod(argv[2], NULL);
			//br_ = (int)ceil(ratio*100);
			br_ = (int)ceil(ratio*10);
			return TCL_OK;
		} else if (strcmp(argv[1], "ranvar-dp") == 0) {
			// Page mod ranvar for dynamic pages
			rvDyn_ = (RandomVariable*)TclObject::lookup(argv[2]);
			return TCL_OK;
		} else if (strcmp(argv[1], "ranvar-sp") == 0) {
			// page mod ranvar for static pages
			rvStatic_= (RandomVariable*)TclObject::lookup(argv[2]);
			return TCL_OK;
		} else if (strcmp(argv[1], "set-reqfile") == 0) {
			return init_req(argv[2]);
		} else if (strcmp(argv[1], "set-pagefile") == 0) {
			return init_page(argv[2]);
		} else if (strcmp(argv[1], "gen-init-modtime") == 0) {
			int id = atoi(argv[2]) % 10;
			if (id >= br_)
				// Static page
				tcl.result("0");
			else
				// Dynamic page
				tcl.resultf("%.17g", 
					    Scheduler::instance().clock());
			return TCL_OK;
		}
	} else {
		if (strcmp(argv[1], "gen-modtime") == 0) {
			if ((rvDyn_ == 0) || (rvStatic_ == 0)) {
				tcl.add_errorf("%s: no page age generator", 
					       name_);
				return TCL_ERROR;
			}
			// int id = atoi(argv[2]) % 100;
			int id = atoi(argv[2]) % 10;
			double mt = strtod(argv[3], NULL);
			if (id >= br_) 
				tcl.resultf("%.17g", mt + rvStatic_->value());
			else 
				tcl.resultf("%.17g", mt + rvDyn_->value());
			return TCL_OK;
		}
	}

	return PagePool::command(argc, argv);
}


// Proxy trace with special method for page modification
static class EPAPagePoolClass : public TclClass {
public:
	EPAPagePoolClass() : TclClass("PagePool/ProxyTrace/epa") {}
	TclObject* create(int, const char*const*) {
		return (new EPATracePagePool());
	}
} class_epapagepool_agent;

int EPATracePagePool::command(int argc, const char*const* argv)
{
	Tcl& tcl = Tcl::instance();
	if (argc == 2) {
		if (strcmp(argv[1], "pick-pagemod") == 0) {
			if (rvDyn_ == 0) {
				tcl.add_errorf("%s: no page age generator",
					       name_);
				return (TCL_ERROR);
			}
			int j = (int)floor(rvDyn_->value());
			//fprintf(stderr, "mod id = %d\n", j/br_*10 + j % br_);
			tcl.resultf("%d", j/br_*10 + j % br_);
			return TCL_OK;
		}
	} else if (argc == 3) {
		if (strcmp(argv[1], "ranvar-dp") == 0) {
			rvDyn_ = (RandomVariable*)TclObject::lookup(argv[2]);
			if (rvDyn_ == 0) {
				tcl.add_errorf("%s: no page age generator",
					       name_);
				return (TCL_ERROR);
			}
			((UniformRandomVariable*)rvDyn_)->setmin(0);
			((UniformRandomVariable*)rvDyn_)->setmax(num_pages_/10*br_ + num_pages_%br_ - 1);
			return TCL_OK;
		}
	} else {
		if (strcmp(argv[1], "gen-modtime") == 0) {
			// Return a very large number
			tcl.resultf("%d", INT_MAX);
			return TCL_OK;
		}
	}
	return ProxyTracePagePool::command(argc, argv);
}