// The contents of this file are subject to the BOINC Public License
// Version 1.0 (the "License"); you may not use this file except in
// compliance with the License. You may obtain a copy of the License at
// http://boinc.berkeley.edu/license_1.0.txt
// 
// Software distributed under the License is distributed on an "AS IS"
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
// License for the specific language governing rights and limitations
// under the License. 
// 
// The Original Code is the Berkeley Open Infrastructure for Network Computing. 
// 
// The Initial Developer of the Original Code is the SETI@home project.
// Portions created by the SETI@home project are Copyright (C) 2002
// University of California at Berkeley. All Rights Reserved. 
// 
// Contributor(s):
//

// "Locality scheduling": a scheduling discipline in which
// there are large sticky input files,
// and many WUs share a single input file.
// If a host already has an input file,
// we try to send him another result that uses that file.
//
// see doc/sched_locality.php


#include <stdio.h>

#include "boinc_db.h"

#include "main.h"
#include "server_types.h"
#include "sched_shmem.h"
#include "sched_send.h"
#include "sched_msgs.h"
#include "sched_locality.h"

static int extract_filename(char* in, char* out) {
    strcpy(out, in);
    char* p = strstr(out, "__");
    if (!p) return -1;
    *p = 0;
    return 0;
}

// Find the app and app_version for the client's platform.
//
static int get_app_version(
    WORKUNIT& wu, APP* &app, APP_VERSION* &avp,
    SCHEDULER_REQUEST& sreq, SCHEDULER_REPLY& reply, PLATFORM& platform,
    WORK_REQ& wreq, SCHED_SHMEM& ss
) {
    bool found;
    if (anonymous(platform)) {
        app = ss.lookup_app(wu.appid);
        found = sreq.has_version(*app);
        if (!found) {
            return -1;
        }
        avp = NULL;
    } else {
        found = find_app_version(wreq, wu, platform, ss, app, avp);
        if (!found) {
            return -1;
        }

        // see if the core client is too old.
        // don't bump the infeasible count because this
        // isn't the result's fault
        //
        if (!app_core_compatible(wreq, *avp)) {
            return -1;
        }
    }
    return 0;
}

// possibly send the client this result
//
static int possibly_send_result(
    DB_RESULT& result,
    SCHEDULER_REQUEST& sreq, SCHEDULER_REPLY& reply, PLATFORM& platform,
    WORK_REQ& wreq, SCHED_SHMEM& ss
) {
    DB_WORKUNIT wu;
    DB_RESULT result2;
    int retval, count;
    char buf[256];
    APP* app;
    APP_VERSION* avp;

    if (config.one_result_per_user_per_wu) {
        retval = wu.lookup_id(result.workunitid);
        if (retval) return retval;
        sprintf(buf, "where userid=%d and workunitid=%d", reply.user.id, wu.id);
        retval = result2.count(count, buf);
        if (retval) return retval;
        if (count > 0) return -1;
    }

    retval = get_app_version(
        wu, app, avp,
        sreq, reply, platform, wreq, ss
    );
    if (retval) return retval;

    retval = add_result_to_reply(result, wu, reply, platform, wreq, app, avp);
    if (retval) return retval;
    return 0;
}

// The client has (or soon will have) the given file.
// Try to send it more results that use the same file
//
static int send_results_for_file(
    char* filename,
    int& nsent,
    SCHEDULER_REQUEST& sreq, SCHEDULER_REPLY& reply, PLATFORM& platform,
    WORK_REQ& wreq, SCHED_SHMEM& ss
) {
    int lastid = 0;
    DB_RESULT result;
    int retval = 0;
    char buf[256];

    nsent = 0;
    while (1) {
        if (!wreq.work_needed(reply)) break;
        boinc_db.start_transaction();
        sprintf(buf,
            "where name like '%s%%' and server_state=%d and id>%d limit 1",
            filename, RESULT_SERVER_STATE_UNSENT, lastid
        );
        retval = result.lookup(buf);
        if (!retval) {
            lastid = result.id;
            if (possibly_send_result(
                result,
                sreq, reply, platform, wreq, ss
            )) {
                nsent++;
            }
        }
        boinc_db.commit_transaction();
        if (retval) break;
    }
    return 0;
}

// The client doesn't have any files for which work is available.
// Pick new file(s) to send.
//
static void send_new_file_work(
    SCHEDULER_REQUEST& sreq, SCHEDULER_REPLY& reply, PLATFORM& platform,
    WORK_REQ& wreq, SCHED_SHMEM& ss
) {
    int retval, lastid=0, nsent;
    DB_RESULT result;
    char filename[256];
    char buf[256];

    while (1) {
        if (!wreq.work_needed(reply)) break;
        boinc_db.start_transaction();
        sprintf(buf,
            "where server_state=%d and id>%d limit 1",
            RESULT_SERVER_STATE_UNSENT, lastid
        );
        retval = result.lookup(buf);
        if (!retval) {
            lastid = result.id;
            possibly_send_result(
                result,
                sreq, reply, platform, wreq, ss
            );
        }
        boinc_db.commit_transaction();
        if (retval) break;

        // try to send more result w/ same file
        //
        retval = extract_filename(result.name, filename);
        if (retval) {
            log_messages.printf(
                SCHED_MSG_LOG::CRITICAL,
                "bad filename: %s", result.name
            );
            continue;
        }
        send_results_for_file(
            filename, nsent,
            sreq, reply, platform, wreq, ss
        );
    }
}

void send_work_locality(
    SCHEDULER_REQUEST& sreq, SCHEDULER_REPLY& reply, PLATFORM& platform,
    WORK_REQ& wreq, SCHED_SHMEM& ss
) {
    unsigned int i;
    int retval, nsent;

    if (sreq.file_infos.size() == 0) {
        send_new_file_work(
            sreq, reply, platform, wreq, ss
        );
    } else {
        for (i=0; i<sreq.file_infos.size(); i++) {
            if (!wreq.work_needed(reply)) break;
            FILE_INFO& fi = sreq.file_infos[i];
            retval = send_results_for_file(
                fi.name, nsent,
                sreq, reply, platform, wreq, ss
            );

            // if we couldn't send any work for this file, tell client
            // to delete it
            //
            if (nsent == 0) {
                reply.file_deletes.push_back(fi);
            }
        }

        // send new files if needed to satisfy work request
        //
        if (wreq.work_needed(reply)) {
            send_new_file_work(
                sreq, reply, platform, wreq, ss
            );
        }
    }
}