lnav/src/session_data.cc

/**
 * Copyright (c) 2013, Timothy Stack
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * * Neither the name of Timothy Stack nor the names of its contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @file session_data.cc
 */

#include "config.h"

#include <stdio.h>
#include <glob.h>
#include <fcntl.h>
#include <sys/types.h>
#include <dirent.h>

#include "spookyhash/SpookyV2.h"

#include <algorithm>

#include "yajlpp.hh"
#include "lnav.hh"
#include "logfile.hh"
#include "sql_util.hh"
#include "lnav_util.hh"
#include "lnav_config.hh"
#include "session_data.hh"
#include "command_executor.hh"

using namespace std;

static const char *LOG_METADATA_NAME = "log_metadata.db";

static const char *BOOKMARK_TABLE_DEF =
    "CREATE TABLE IF NOT EXISTS bookmarks (\n"
    "    log_time datetime,\n"
    "    log_format varchar(64),\n"
    "    log_hash varchar(128),\n"
    "    session_time integer,\n"
    "    part_name text,\n"
    "    access_time datetime DEFAULT CURRENT_TIMESTAMP,\n"
    "\n"
    "    PRIMARY KEY (log_time, log_format, log_hash, session_time)\n"
    ");\n"
    "CREATE TABLE IF NOT EXISTS time_offset (\n"
    "    log_time datetime,\n"
    "    log_format varchar(64),\n"
    "    log_hash varchar(128),\n"
    "    session_time integer,\n"
    "    offset_sec integer,\n"
    "    offset_usec integer,\n"
    "    access_time datetime DEFAULT CURRENT_TIMESTAMP,\n"
    "\n"
    "    PRIMARY KEY (log_time, log_format, log_hash, session_time)\n"
    ");\n";

static const char *BOOKMARK_LRU_STMT =
    "DELETE FROM bookmarks WHERE access_time <= "
    "  (SELECT access_time FROM bookmarks "
    "   ORDER BY access_time DESC LIMIT 1 OFFSET 50000)";

static const size_t MAX_SESSIONS           = 8;
static const size_t MAX_SESSION_FILE_COUNT = 256;

typedef std::vector<std::pair<int, string> > timestamped_list_t;

static std::vector<content_line_t> marked_session_lines;
static std::vector<content_line_t> offset_session_lines;

static bool bind_line(sqlite3 *db,
                      sqlite3_stmt *stmt,
                      content_line_t cl,
                      time_t session_time)
{
    logfile_sub_source &lss = lnav_data.ld_log_source;
    logfile::iterator line_iter;
    logfile *lf;

    lf = lss.find(cl);

    if (lf == NULL) {
        return false;
    }

    line_iter = lf->begin() + cl;

    char timestamp[64];

    sql_strftime(timestamp, sizeof(timestamp),
                 lf->original_line_time(line_iter), 'T');
    if (sqlite3_bind_text(stmt, 1,
                          timestamp, strlen(timestamp),
                          SQLITE_TRANSIENT) != SQLITE_OK) {
        log_error("could not bind log time -- %s\n",
                sqlite3_errmsg(db));
        return false;
    }

    intern_string_t format_name = lf->get_format()->get_name();

    if (sqlite3_bind_text(stmt, 2,
                          format_name.get(), format_name.size(),
                          SQLITE_TRANSIENT) != SQLITE_OK) {
        log_error("could not bind log format -- %s\n",
                    sqlite3_errmsg(db));
        return false;
    }

    shared_buffer_ref sbr;
    lf->read_line(line_iter, sbr);
    std::string line_hash = hash_bytes(sbr.get_data(), sbr.length(),
                                       &cl, sizeof(cl),
                                       NULL);

    if (sqlite3_bind_text(stmt, 3,
                          line_hash.c_str(), line_hash.length(),
                          SQLITE_TRANSIENT) != SQLITE_OK) {
        log_error("could not bind log hash -- %s\n",
                sqlite3_errmsg(db));
        return false;
    }

    if (sqlite3_bind_int64(stmt, 4, session_time) != SQLITE_OK) {
        log_error("could not bind session time -- %s\n",
                sqlite3_errmsg(db));
        return false;
    }

    return true;
}

struct session_file_info {
    session_file_info(int timestamp,
                      const string &id,
                      const string &path)
        : sfi_timestamp(timestamp), sfi_id(id), sfi_path(path) {};

    bool operator<(const session_file_info &other) const
    {
        if (this->sfi_timestamp < other.sfi_timestamp) {
            return true;
        }
        if (this->sfi_path < other.sfi_path) {
            return true;
        }
        return false;
    };

    int    sfi_timestamp;
    string sfi_id;
    string sfi_path;
};

static void cleanup_session_data(void)
{
    static_root_mem<glob_t, globfree>   session_file_list;
    std::list<struct session_file_info> session_info_list;
    map<string, int> session_count;
    string           session_file_pattern;

    session_file_pattern = dotlnav_path("*-*.ts*.json");

    if (glob(session_file_pattern.c_str(),
             0,
             NULL,
             session_file_list.inout()) == 0) {
        for (size_t lpc = 0; lpc < session_file_list->gl_pathc; lpc++) {
            const char *path = session_file_list->gl_pathv[lpc];
            char        hash_id[64];
            int         timestamp;
            const char *base;

            base = strrchr(path, '/') + 1;
            if (sscanf(base, "file-%63[^.].ts%d.json",
                       hash_id, &timestamp) == 2) {
                session_count[hash_id] += 1;
                session_info_list.push_back(session_file_info(
                                                timestamp, hash_id, path));
            }
            if (sscanf(base,
                       "view-info-%63[^.].ts%d.ppid%*d.json",
                       hash_id,
                       &timestamp) == 2) {
                session_count[hash_id] += 1;
                session_info_list.push_back(session_file_info(
                                                timestamp, hash_id, path));
            }
        }
    }

    session_info_list.sort();

    size_t session_loops = 0;

    while (session_info_list.size() > MAX_SESSION_FILE_COUNT) {
        const session_file_info &front = session_info_list.front();

        session_loops += 1;
        if (session_loops < MAX_SESSION_FILE_COUNT &&
            session_count[front.sfi_id] == 1) {
            session_info_list.splice(session_info_list.end(),
                                     session_info_list,
                                     session_info_list.begin());
        }
        else {
            if (remove(front.sfi_path.c_str()) != 0) {
                log_error(
                        "Unable to remove session file: %s -- %s\n",
                        front.sfi_path.c_str(),
                        strerror(errno));
            }
            session_count[front.sfi_id] -= 1;
            session_info_list.pop_front();
        }
    }

    session_info_list.sort();

    while (session_info_list.size() > MAX_SESSION_FILE_COUNT) {
        const session_file_info &front = session_info_list.front();

        if (remove(front.sfi_path.c_str()) != 0) {
            log_error(
                    "Unable to remove session file: %s -- %s\n",
                    front.sfi_path.c_str(),
                    strerror(errno));
        }
        session_count[front.sfi_id] -= 1;
        session_info_list.pop_front();
    }
}

void init_session(void)
{
    byte_array<2, uint64> hash;
    SpookyHash context;

    lnav_data.ld_session_time = time(NULL);

    context.Init(0, 0);
    hash_updater updater(&context);
    for (map<string, logfile_open_options>::iterator iter = lnav_data.ld_file_names.begin();
         iter != lnav_data.ld_file_names.end();
         ++iter) {
        updater(iter->first);
    }
    context.Final(hash.out(0), hash.out(1));

    lnav_data.ld_session_id = hash.to_string();

    log_info("init_session: time=%d; id=%s", lnav_data.ld_session_time,
        lnav_data.ld_session_id.c_str());
}

void scan_sessions(void)
{
    std::list<session_pair_t> &session_file_names =
        lnav_data.ld_session_file_names;

    static_root_mem<glob_t, globfree>   view_info_list;
    std::list<session_pair_t>::iterator iter;
    char   view_info_pattern_base[128];
    string view_info_pattern;
    string old_session_name;
    int    index;

    cleanup_session_data();

    if (lnav_data.ld_session_file_index >= 0 &&
        lnav_data.ld_session_file_index < (int)session_file_names.size()) {
        iter = session_file_names.begin();

        advance(iter, lnav_data.ld_session_file_index);
        old_session_name = iter->second;
    }

    session_file_names.clear();

    snprintf(view_info_pattern_base, sizeof(view_info_pattern_base),
             "view-info-%s.*.json",
             lnav_data.ld_session_id.c_str());
    view_info_pattern = dotlnav_path(view_info_pattern_base);
    if (glob(view_info_pattern.c_str(), 0, NULL,
             view_info_list.inout()) == 0) {
        for (size_t lpc = 0; lpc < view_info_list->gl_pathc; lpc++) {
            const char *path = view_info_list->gl_pathv[lpc];
            int         timestamp, ppid;
            const char *base;

            base = strrchr(path, '/') + 1;
            if (sscanf(base,
                       "view-info-%*[^.].ts%d.ppid%d.json",
                       &timestamp,
                       &ppid) == 2) {
                ppid_time_pair_t ptp;

                ptp.first  = (ppid == getppid()) ? 1 : 0;
                ptp.second = timestamp;
                session_file_names.push_back(make_pair(ptp, path));
            }
        }
    }

    session_file_names.sort();

    while (session_file_names.size() > MAX_SESSIONS) {
        const std::string &name = session_file_names.front().second;

        if (remove(name.c_str()) != 0) {
            log_error(
                    "Unable to remove session: %s -- %s\n",
                    name.c_str(),
                    strerror(errno));
        }
        session_file_names.pop_front();
    }

    lnav_data.ld_session_file_index = ((int)session_file_names.size()) - 1;

    for (index = 0, iter = session_file_names.begin();
         iter != session_file_names.end();
         index++, ++iter) {
        if (iter->second == old_session_name) {
            lnav_data.ld_session_file_index = index;
            break;
        }
    }
}

static void load_time_bookmarks(void)
{
    logfile_sub_source &lss = lnav_data.ld_log_source;
    std::map<content_line_t, bookmark_metadata> &bm_meta = lss.get_user_bookmark_metadata();
    auto_mem<sqlite3, sqlite_close_wrapper> db;
    string db_path = dotlnav_path(LOG_METADATA_NAME);
    auto_mem<sqlite3_stmt> stmt(sqlite3_finalize);
    logfile_sub_source::iterator file_iter;

    log_info("loading bookmark db: %s", db_path.c_str());

    if (sqlite3_open(db_path.c_str(), db.out()) != SQLITE_OK) {
        return;
    }

    if (sqlite3_prepare_v2(db.in(),
                           "SELECT *,session_time=? as same_session FROM bookmarks WHERE "
                           " log_time between ? and ? and log_format = ? "
                           " ORDER BY same_session DESC, session_time DESC",
                           -1,
                           stmt.out(),
                           NULL) != SQLITE_OK) {
        log_error(
                "could not prepare bookmark select statemnt -- %s\n",
                sqlite3_errmsg(db));
        return;
    }

    for (file_iter = lnav_data.ld_log_source.begin();
         file_iter != lnav_data.ld_log_source.end();
         ++file_iter) {
        char low_timestamp[64], high_timestamp[64];
        logfile *lf = (*file_iter)->get_file();
        content_line_t base_content_line;

        if (lf == NULL)
            continue;

        base_content_line = lss.get_file_base_content_line(file_iter);

        logfile::iterator line_iter = lf->begin();

        sql_strftime(low_timestamp, sizeof(low_timestamp),
                     lf->original_line_time(line_iter), 'T');

        if (sqlite3_bind_int64(stmt.in(), 1, lnav_data.ld_session_load_time) != SQLITE_OK) {
            log_error("could not bind session time -- %s\n",
                    sqlite3_errmsg(db.in()));
            return;
        }

        if (sqlite3_bind_text(stmt.in(), 2,
                              low_timestamp, strlen(low_timestamp),
                              SQLITE_TRANSIENT) != SQLITE_OK) {
            log_error("could not bind low log time -- %s\n",
                    sqlite3_errmsg(db.in()));
            return;
        }

        line_iter = lf->end();
        --line_iter;
        sql_strftime(high_timestamp, sizeof(high_timestamp),
                     lf->original_line_time(line_iter), 'T');

        if (sqlite3_bind_text(stmt.in(), 3,
                              high_timestamp, strlen(high_timestamp),
                              SQLITE_TRANSIENT) != SQLITE_OK) {
            log_error("could not bind high log time -- %s\n",
                    sqlite3_errmsg(db.in()));
            return;
        }

        intern_string_t format_name = lf->get_format()->get_name();

        if (sqlite3_bind_text(stmt.in(), 4,
                              format_name.get(), format_name.size(),
                              SQLITE_TRANSIENT) != SQLITE_OK) {
            log_error("could not bind log format -- %s\n",
                    sqlite3_errmsg(db.in()));
            return;
        }

        date_time_scanner dts;
        bool done = false;
        string line;
        int64_t last_mark_time = -1;

        while (!done) {
            int rc = sqlite3_step(stmt.in());

            switch (rc) {
            case SQLITE_OK:
            case SQLITE_DONE:
                done = true;
                break;

            case SQLITE_ROW: {
                const char *log_time = (const char *)sqlite3_column_text(stmt.in(), 0);
                const char *log_hash = (const char *)sqlite3_column_text(stmt.in(), 2);
                const char *part_name = (const char *)sqlite3_column_text(stmt.in(), 4);
                int64_t mark_time = sqlite3_column_int64(stmt.in(), 3);
                struct timeval log_tv;
                struct exttm log_tm;

                if (last_mark_time == -1) {
                    last_mark_time = mark_time;
                }
                else if (last_mark_time != mark_time) {
                    done = true;
                    continue;
                }

                if (part_name == NULL) {
                    continue;
                }

                if (!dts.scan(log_time, strlen(log_time), NULL, &log_tm, log_tv)) {
                    continue;
                }

                line_iter = lower_bound(lf->begin(),
                                        lf->end(),
                                        log_tv);
                while (line_iter != lf->end()) {
                    struct timeval line_tv = line_iter->get_timeval();

                    if ((line_tv.tv_sec != log_tv.tv_sec) ||
                        (line_tv.tv_usec != log_tv.tv_usec)) {
                        break;
                    }

                    shared_buffer_ref sbr;
                    content_line_t cl = content_line_t(std::distance(lf->begin(), line_iter));
                    lf->read_line(line_iter, sbr);

                    string line_hash = hash_bytes(sbr.get_data(), sbr.length(),
                                                  &cl, sizeof(cl),
                                                  NULL);

                    if (line_hash == log_hash) {
                        content_line_t line_cl = content_line_t(
                            base_content_line + std::distance(lf->begin(), line_iter));

                        if (part_name != NULL && part_name[0] != '\0') {
                            lss.set_user_mark(&textview_curses::BM_PARTITION,
                                line_cl);
                            bm_meta[line_cl].bm_name = part_name;
                        }
                        else {
                            marked_session_lines.push_back(line_cl);
                            lss.set_user_mark(&textview_curses::BM_USER,
                                line_cl);

                        }
                    }

                    ++line_iter;
                }
                break;
            }

            default:
                {
                    const char *errmsg;

                    errmsg = sqlite3_errmsg(lnav_data.ld_db);
                    log_error(
                            "bookmark select error: code %d -- %s\n",
                            rc,
                            errmsg);
                    done = true;
                }
                break;
            }
        }

        sqlite3_reset(stmt.in());
    }

    if (sqlite3_prepare_v2(db.in(),
                           "SELECT *,session_time=? as same_session FROM time_offset WHERE "
                           " log_time between ? and ? and log_format = ? "
                           " ORDER BY same_session DESC, session_time DESC",
                           -1,
                           stmt.out(),
                           NULL) != SQLITE_OK) {
        log_error(
                "could not prepare time_offset select statemnt -- %s\n",
                sqlite3_errmsg(db));
        return;
    }

    for (file_iter = lnav_data.ld_log_source.begin();
         file_iter != lnav_data.ld_log_source.end();
         ++file_iter) {
        char low_timestamp[64], high_timestamp[64];
        logfile *lf = (*file_iter)->get_file();
        content_line_t base_content_line;

        if (lf == NULL)
            continue;

        lss.find(lf->get_filename().c_str(), base_content_line);

        logfile::iterator line_iter = lf->begin();

        sql_strftime(low_timestamp, sizeof(low_timestamp),
                     lf->original_line_time(line_iter), 'T');

        if (sqlite3_bind_int64(stmt.in(), 1, lnav_data.ld_session_load_time) != SQLITE_OK) {
            log_error("could not bind session time -- %s\n",
                    sqlite3_errmsg(db.in()));
            return;
        }

        if (sqlite3_bind_text(stmt.in(), 2,
                              low_timestamp, strlen(low_timestamp),
                              SQLITE_TRANSIENT) != SQLITE_OK) {
            log_error("could not bind low log time -- %s\n",
                    sqlite3_errmsg(db.in()));
            return;
        }

        line_iter = lf->end();
        --line_iter;
        sql_strftime(high_timestamp, sizeof(high_timestamp),
                     lf->original_line_time(line_iter), 'T');

        if (sqlite3_bind_text(stmt.in(), 3,
                              high_timestamp, strlen(high_timestamp),
                              SQLITE_TRANSIENT) != SQLITE_OK) {
            log_error("could not bind high log time -- %s\n",
                    sqlite3_errmsg(db.in()));
            return;
        }

        intern_string_t format_name = lf->get_format()->get_name();

        if (sqlite3_bind_text(stmt.in(), 4,
                              format_name.get(), format_name.size(),
                              SQLITE_TRANSIENT) != SQLITE_OK) {
            log_error("could not bind log format -- %s\n",
                    sqlite3_errmsg(db.in()));
            return;
        }

        date_time_scanner dts;
        bool done = false;
        string line;
        int64_t last_mark_time = -1;

        while (!done) {
            int rc = sqlite3_step(stmt.in());

            switch (rc) {
            case SQLITE_OK:
            case SQLITE_DONE:
                done = true;
                break;

            case SQLITE_ROW: {
                const char *log_time = (const char *)sqlite3_column_text(stmt.in(), 0);
                const char *log_hash = (const char *)sqlite3_column_text(stmt.in(), 2);
                int64_t mark_time = sqlite3_column_int64(stmt.in(), 3);
                struct timeval log_tv;
                struct exttm log_tm;

                if (last_mark_time == -1) {
                    last_mark_time = mark_time;
                }
                else if (last_mark_time != mark_time) {
                    done = true;
                    continue;
                }

                if (sqlite3_column_type(stmt.in(), 4) == SQLITE_NULL) {
                    continue;
                }

                if (!dts.scan(log_time, strlen(log_time), NULL, &log_tm, log_tv)) {
                    continue;
                }

                line_iter = lower_bound(lf->begin(),
                                        lf->end(),
                                        log_tv);
                while (line_iter != lf->end()) {
                    struct timeval line_tv = line_iter->get_timeval();

                    if ((line_tv.tv_sec != log_tv.tv_sec) ||
                        (line_tv.tv_usec != log_tv.tv_usec)) {
                        break;
                    }

                    lf->read_line(line_iter, line);

                    string line_hash = hash_string(line);
                    if (line_hash == log_hash) {
                        int file_line = std::distance(lf->begin(), line_iter);
                        content_line_t line_cl = content_line_t(
                            base_content_line + file_line);
                        struct timeval offset;

                        offset_session_lines.push_back(line_cl);
                        offset.tv_sec = sqlite3_column_int64(stmt.in(), 4);
                        offset.tv_usec = sqlite3_column_int64(stmt.in(), 5);
                        lf->adjust_content_time(file_line, offset);
                    }

                    ++line_iter;
                }
                break;
            }

            default:
                {
                    const char *errmsg;

                    errmsg = sqlite3_errmsg(lnav_data.ld_db);
                    log_error(
                            "bookmark select error: code %d -- %s\n",
                            rc,
                            errmsg);
                    done = true;
                }
                break;
            }
        }

        sqlite3_reset(stmt.in());
    }
}

static int read_save_time(yajlpp_parse_context *ypc, long long value)
{
    lnav_data.ld_session_save_time = value;

    return 1;
}

static int read_time_offset(yajlpp_parse_context *ypc, int value)
{
    return 1;
}

static int read_files(yajlpp_parse_context *ypc, const unsigned char *str, size_t len)
{
    return 1;
}

static int read_last_search(yajlpp_parse_context *ypc, const unsigned char *str, size_t len)
{
    string       regex        = std::string((const char *)str, len);
    const char **view_name;
    int          view_index;

    view_name = find(lnav_view_strings,
                     lnav_view_strings + LNV__MAX,
                     ypc->get_path_fragment(-2));
    view_index = view_name - lnav_view_strings;

    if (view_index < LNV__MAX && !regex.empty()) {
        execute_search((lnav_view_t)view_index, regex);
        lnav_data.ld_views[view_index].set_follow_search(false);
    }

    return 1;
}

static int read_top_line(yajlpp_parse_context *ypc, long long value)
{
    const char **         view_name;
    int view_index;

    view_name = find(lnav_view_strings,
                     lnav_view_strings + LNV__MAX,
                     ypc->get_path_fragment(-2));
    view_index = view_name - lnav_view_strings;
    if (view_index < LNV__MAX) {
        textview_curses &tc = lnav_data.ld_views[view_index];

        if (value != -1 && value < tc.get_inner_height()) {
            tc.set_top(vis_line_t(value));
        }
    }

    return 1;
}

static int read_word_wrap(yajlpp_parse_context *ypc, int value)
{
    const char **         view_name;
    int view_index;

    view_name = find(lnav_view_strings,
                     lnav_view_strings + LNV__MAX,
                     ypc->get_path_fragment(-2));
    view_index = view_name - lnav_view_strings;
    if (view_index == LNV_HELP) {

    }
    else if (view_index < LNV__MAX) {
        textview_curses &tc = lnav_data.ld_views[view_index];

        tc.set_word_wrap(value);
    }

    return 1;
}

static int read_commands(yajlpp_parse_context *ypc, const unsigned char *str, size_t len)
{
    std::string cmdline = std::string((const char *)str, len);
    const char **         view_name;
    int view_index;

    view_name = find(lnav_view_strings,
            lnav_view_strings + LNV__MAX,
            ypc->get_path_fragment(-3));
    view_index = view_name - lnav_view_strings;
    bool active = ensure_view(&lnav_data.ld_views[view_index]);
    execute_command(cmdline);
    if (!active) {
        lnav_data.ld_view_stack.pop();
    }

    return 1;
}

static struct json_path_handler view_handlers[] = {
        json_path_handler("top_line"),

        json_path_handler()
};

static struct json_path_handler view_info_handlers[] = {
    json_path_handler("/save-time",               read_save_time),
    json_path_handler("/time-offset",             read_time_offset),
    json_path_handler("/files#",                  read_files),
    json_path_handler("/views/([^/]+)/top_line",  read_top_line),
    json_path_handler("/views/([^/]+)/search",    read_last_search),
    json_path_handler("/views/([^/]+)/word_wrap", read_word_wrap),
    json_path_handler("/views/([^/]+)/commands#", read_commands),

    json_path_handler()
};

void load_session(void)
{
    std::list<session_pair_t>::iterator sess_iter;
    yajl_handle          handle;
    auto_fd fd;

    if (lnav_data.ld_session_file_names.empty()) {
        load_time_bookmarks();
        return;
    }

    sess_iter = lnav_data.ld_session_file_names.begin();
    advance(sess_iter, lnav_data.ld_session_file_index);
    lnav_data.ld_session_load_time = sess_iter->first.second;
    lnav_data.ld_session_save_time = sess_iter->first.second;
    string &view_info_name = sess_iter->second;

    yajlpp_parse_context ypc(view_info_name, view_info_handlers);
    handle    = yajl_alloc(&ypc.ypc_callbacks, NULL, &ypc);

    load_time_bookmarks();

    if ((fd = open(view_info_name.c_str(), O_RDONLY)) < 0) {
        perror("cannot open session file");
    }
    else {
        unsigned char buffer[1024];
        ssize_t        rc;

        log_info("loading session file: %s", view_info_name.c_str());
        while ((rc = read(fd, buffer, sizeof(buffer))) > 0) {
            yajl_parse(handle, buffer, rc);
        }
        yajl_complete_parse(handle);
    }
    yajl_free(handle);
}

static void yajl_writer(void *context, const char *str, size_t len)
{
    FILE *file = (FILE *)context;

    fwrite(str, len, 1, file);
}

static void save_user_bookmarks(
    sqlite3 *db, sqlite3_stmt *stmt, bookmark_vector<content_line_t> &user_marks)
{
    logfile_sub_source &lss = lnav_data.ld_log_source;
    std::map<content_line_t, bookmark_metadata> &bm_meta =
        lss.get_user_bookmark_metadata();
    bookmark_vector<content_line_t>::iterator iter;

    for (iter = user_marks.begin(); iter != user_marks.end(); ++iter) {
        std::map<content_line_t, bookmark_metadata>::iterator meta_iter;
        logfile::iterator line_iter;
        content_line_t cl = *iter;

        meta_iter = bm_meta.find(cl);

        marked_session_lines.push_back(cl);

        if (!bind_line(db, stmt, cl, lnav_data.ld_session_time)) {
            continue;
        }

        if (meta_iter == bm_meta.end()) {
            if (sqlite3_bind_text(stmt, 5, "", 0, SQLITE_TRANSIENT) != SQLITE_OK) {
                log_error("could not bind log hash -- %s\n",
                        sqlite3_errmsg(db));
                return;
            }
        }
        else {
            if (sqlite3_bind_text(stmt, 5,
                                  meta_iter->second.bm_name.c_str(),
                                  meta_iter->second.bm_name.length(),
                                  SQLITE_TRANSIENT) != SQLITE_OK) {
                log_error("could not bind log hash -- %s\n",
                        sqlite3_errmsg(db));
                return;
            }
        }

        if (sqlite3_step(stmt) != SQLITE_DONE) {
            log_error(
                    "could not execute bookmark insert statement -- %s\n",
                    sqlite3_errmsg(db));
            return;
        }

        sqlite3_reset(stmt);
    }

}

static void save_time_bookmarks(void)
{
    auto_mem<sqlite3, sqlite_close_wrapper> db;
    string db_path = dotlnav_path(LOG_METADATA_NAME);
    auto_mem<char, sqlite3_free> errmsg;
    auto_mem<sqlite3_stmt> stmt(sqlite3_finalize);

    if (sqlite3_open(db_path.c_str(), db.out()) != SQLITE_OK) {
        log_error("unable to open bookmark DB -- %s\n", db_path.c_str());
        return;
    }

    if (sqlite3_exec(db.in(), BOOKMARK_TABLE_DEF, NULL, NULL, errmsg.out()) != SQLITE_OK) {
        log_error("unable to make bookmark table -- %s\n", errmsg.in());
        return;
    }

    if (sqlite3_exec(db.in(), "BEGIN TRANSACTION", NULL, NULL, errmsg.out()) != SQLITE_OK) {
        log_error("unable to begin transaction -- %s\n", errmsg.in());
        return;
    }

    logfile_sub_source &lss = lnav_data.ld_log_source;
    bookmarks<content_line_t>::type &bm = lss.get_user_bookmarks();

    if (sqlite3_prepare_v2(db.in(),
                           "DELETE FROM bookmarks WHERE "
                           " log_time = ? and log_format = ? and log_hash = ? "
                           " and session_time = ?",
                           -1,
                           stmt.out(),
                           NULL) != SQLITE_OK) {
        log_error(
                "could not prepare bookmark delete statemnt -- %s\n",
                sqlite3_errmsg(db));
        return;
    }

    for (std::vector<content_line_t>::iterator cl_iter = marked_session_lines.begin();
         cl_iter != marked_session_lines.end();
         ++cl_iter) {
        if (!bind_line(
            db.in(), stmt.in(), *cl_iter, lnav_data.ld_session_time)) {
            continue;
        }

        if (sqlite3_step(stmt.in()) != SQLITE_DONE) {
            log_error(
                    "could not execute bookmark insert statement -- %s\n",
                    sqlite3_errmsg(db));
            return;
        }

        sqlite3_reset(stmt.in());
    }

    marked_session_lines.clear();

    if (sqlite3_prepare_v2(db.in(),
                           "REPLACE INTO bookmarks"
                           " (log_time, log_format, log_hash, session_time, part_name)"
                           " VALUES (?, ?, ?, ?, ?)",
                           -1,
                           stmt.out(),
                           NULL) != SQLITE_OK) {
        log_error(
                "could not prepare bookmark replace statemnt -- %s\n",
                sqlite3_errmsg(db));
        return;
    }

    {
        logfile_sub_source::iterator file_iter;

        for (file_iter = lnav_data.ld_log_source.begin();
             file_iter != lnav_data.ld_log_source.end();
             ++file_iter) {
            logfile *lf = (*file_iter)->get_file();
            content_line_t base_content_line;

            if (lf == NULL)
                continue;

            base_content_line = lss.get_file_base_content_line(file_iter);
            base_content_line = content_line_t(
                base_content_line + lf->size() - 1);

            if (!bind_line(db.in(), stmt.in(), base_content_line,
                lnav_data.ld_session_time)) {
                continue;
            }

            if (sqlite3_bind_null(stmt.in(), 5) != SQLITE_OK) {
                log_error("could not bind log hash -- %s\n",
                        sqlite3_errmsg(db.in()));
                return;
            }

            if (sqlite3_step(stmt.in()) != SQLITE_DONE) {
                log_error(
                        "could not execute bookmark insert statement -- %s\n",
                        sqlite3_errmsg(db));
                return;
            }

            sqlite3_reset(stmt.in());
        }
    }

    save_user_bookmarks(db.in(), stmt.in(), bm[&textview_curses::BM_USER]);
    save_user_bookmarks(db.in(), stmt.in(), bm[&textview_curses::BM_PARTITION]);

    if (sqlite3_prepare_v2(db.in(),
                           "DELETE FROM time_offset WHERE "
                           " log_time = ? and log_format = ? and log_hash = ? "
                           " and session_time = ?",
                           -1,
                           stmt.out(),
                           NULL) != SQLITE_OK) {
        log_error(
                "could not prepare time_offset delete statemnt -- %s\n",
                sqlite3_errmsg(db));
        return;
    }

    for (std::vector<content_line_t>::iterator cl_iter = offset_session_lines.begin();
         cl_iter != offset_session_lines.end();
         ++cl_iter) {
        if (!bind_line(
            db.in(), stmt.in(), *cl_iter, lnav_data.ld_session_time)) {
            continue;
        }

        if (sqlite3_step(stmt.in()) != SQLITE_DONE) {
            log_error(
                    "could not execute bookmark insert statement -- %s\n",
                    sqlite3_errmsg(db));
            return;
        }

        sqlite3_reset(stmt.in());
    }

    offset_session_lines.clear();

    if (sqlite3_prepare_v2(db.in(),
                           "REPLACE INTO time_offset"
                           " (log_time, log_format, log_hash, session_time, offset_sec, offset_usec)"
                           " VALUES (?, ?, ?, ?, ?, ?)",
                           -1,
                           stmt.out(),
                           NULL) != SQLITE_OK) {
        log_error(
                "could not prepare time_offset replace statemnt -- %s\n",
                sqlite3_errmsg(db));
        return;
    }

    {
        logfile_sub_source::iterator file_iter;

        for (file_iter = lnav_data.ld_log_source.begin();
             file_iter != lnav_data.ld_log_source.end();
             ++file_iter) {
            logfile *lf = (*file_iter)->get_file();
            content_line_t base_content_line;

            if (lf == NULL)
                continue;

            base_content_line = lss.get_file_base_content_line(file_iter);

            if (!bind_line(db.in(), stmt.in(), base_content_line,
                lnav_data.ld_session_time)) {
                continue;
            }

            if (sqlite3_bind_null(stmt.in(), 5) != SQLITE_OK) {
                log_error("could not bind log hash -- %s\n",
                        sqlite3_errmsg(db.in()));
                return;
            }

            if (sqlite3_bind_null(stmt.in(), 6) != SQLITE_OK) {
                log_error("could not bind log hash -- %s\n",
                        sqlite3_errmsg(db.in()));
                return;
            }

            if (sqlite3_step(stmt.in()) != SQLITE_DONE) {
                log_error(
                        "could not execute bookmark insert statement -- %s\n",
                        sqlite3_errmsg(db));
                return;
            }

            sqlite3_reset(stmt.in());
        }
    }

    for (logfile_sub_source::iterator file_iter = lss.begin();
         file_iter != lss.end();
         ++file_iter) {
        logfile::iterator line_iter;

        if ((*file_iter)->get_file() == NULL)
            continue;

        logfile *lf = (*file_iter)->get_file();

        if (!lf->is_time_adjusted())
            continue;

        line_iter = lf->begin() + lf->get_time_offset_line();

        char timestamp[64];

        sql_strftime(timestamp, sizeof(timestamp),
                     lf->original_line_time(line_iter), 'T');
        if (sqlite3_bind_text(stmt.in(), 1,
                              timestamp, strlen(timestamp),
                              SQLITE_TRANSIENT) != SQLITE_OK) {
            log_error("could not bind log time -- %s\n",
                    sqlite3_errmsg(db.in()));
            return;
        }

        intern_string_t format_name = lf->get_format()->get_name();

        if (sqlite3_bind_text(stmt.in(), 2,
                              format_name.get(), format_name.size(),
                              SQLITE_TRANSIENT) != SQLITE_OK) {
            log_error("could not bind log format -- %s\n",
                    sqlite3_errmsg(db.in()));
            return;
        }

        std::string line_hash = hash_string(lf->read_line(line_iter));

        if (sqlite3_bind_text(stmt.in(), 3,
                              line_hash.c_str(), line_hash.length(),
                              SQLITE_TRANSIENT) != SQLITE_OK) {
            log_error("could not bind log hash -- %s\n",
                    sqlite3_errmsg(db.in()));
            return;
        }

        if (sqlite3_bind_int64(stmt.in(), 4, lnav_data.ld_session_time) != SQLITE_OK) {
            log_error("could not bind session time -- %s\n",
                    sqlite3_errmsg(db.in()));
            return;
        }

        struct timeval offset = lf->get_time_offset();

        if (sqlite3_bind_int64(stmt.in(), 5, offset.tv_sec) != SQLITE_OK) {
            log_error("could not bind offset_sec -- %s\n",
                    sqlite3_errmsg(db.in()));
            return;
        }

        if (sqlite3_bind_int64(stmt.in(), 6, offset.tv_usec) != SQLITE_OK) {
            log_error("could not bind offset_usec -- %s\n",
                    sqlite3_errmsg(db.in()));
            return;
        }

        if (sqlite3_step(stmt.in()) != SQLITE_DONE) {
            log_error(
                    "could not execute bookmark insert statement -- %s\n",
                    sqlite3_errmsg(db));
            return;
        }

        sqlite3_reset(stmt.in());
    }

    if (sqlite3_exec(db.in(), "COMMIT", NULL, NULL, errmsg.out()) != SQLITE_OK) {
        log_error("unable to begin transaction -- %s\n", errmsg.in());
        return;
    }

    if (sqlite3_exec(db.in(), BOOKMARK_LRU_STMT, NULL, NULL, errmsg.out()) != SQLITE_OK) {
        log_error("unable to delete old bookmarks -- %s\n", errmsg.in());
        return;
    }
}

void save_session(void)
{
    string view_file_name, view_file_tmp_name;

    auto_mem<FILE> file(fclose);
    char           view_base_name[256];
    yajl_gen       handle = NULL;

    save_time_bookmarks();

    /* TODO: save the last search query */

    snprintf(view_base_name, sizeof(view_base_name),
             "view-info-%s.ts%ld.ppid%d.json",
             lnav_data.ld_session_id.c_str(),
             lnav_data.ld_session_time,
             getppid());

    view_file_name     = dotlnav_path(view_base_name);
    view_file_tmp_name = view_file_name + ".tmp";

    if ((file = fopen(view_file_tmp_name.c_str(), "w")) == NULL) {
        perror("Unable to open session file");
    }
    else if ((handle = yajl_gen_alloc(NULL)) == NULL) {
        perror("Unable to create yajl_gen object");
    }
    else {
        yajl_gen_config(handle,
                        yajl_gen_print_callback, yajl_writer, file.in());

        {
            yajlpp_map root_map(handle);

            root_map.gen("save-time");
            root_map.gen((long long)time(NULL));

            root_map.gen("time-offset");
            root_map.gen(lnav_data.ld_log_source.is_time_offset_enabled());

            root_map.gen("files");

            {
                yajlpp_array file_list(handle);

                for (map<string, logfile_open_options>::iterator iter = lnav_data.ld_file_names.begin();
                     iter != lnav_data.ld_file_names.end();
                     ++iter) {
                    file_list.gen(iter->first);
                }
            }

            root_map.gen("views");

            {
                yajlpp_map top_view_map(handle);

                for (int lpc = 0; lpc < LNV__MAX; lpc++) {
                    textview_curses &tc = lnav_data.ld_views[lpc];
                    unsigned long    width;
                    vis_line_t       height;

                    top_view_map.gen(lnav_view_strings[lpc]);

                    yajlpp_map view_map(handle);

                    view_map.gen("top_line");

                    tc.get_dimensions(height, width);
                    if (tc.get_top() >= tc.get_top_for_last_row()) {
                        view_map.gen(-1LL);
                    }
                    else{
                        view_map.gen((long long)tc.get_top());
                    }

                    view_map.gen("search");
                    view_map.gen(lnav_data.ld_last_search[lpc]);

                    view_map.gen("word_wrap");
                    view_map.gen(tc.get_word_wrap());

                    text_sub_source *tss = tc.get_sub_source();
                    if (tss == NULL) {
                        continue;
                    }

                    filter_stack::iterator filter_iter;
                    filter_stack &fs = tss->get_filters();

                    view_map.gen("commands");
                    yajlpp_array cmd_array(handle);

                    for (filter_iter = fs.begin();
                         filter_iter != fs.end();
                         ++filter_iter) {
                        if (!(*filter_iter)->is_enabled()) {
                            continue;
                        }

                        cmd_array.gen((*filter_iter)->to_command());
                    }

                    if (lpc == LNV_LOG) {
                        textview_curses::highlight_map_t &hmap =
                                lnav_data.ld_views[LNV_LOG].get_highlights();
                        textview_curses::highlight_map_t::iterator hl_iter;

                        for (hl_iter = hmap.begin();
                             hl_iter != hmap.end();
                             ++hl_iter) {
                            if (hl_iter->first[0] == '$') {
                                continue;
                            }
                            cmd_array.gen("highlight " + hl_iter->first);
                        }
                    }
                }
            }
        }

        yajl_gen_clear(handle);
        yajl_gen_free(handle);

        fclose(file.release());

        log_perror(rename(view_file_tmp_name.c_str(), view_file_name.c_str()));

        log_debug("Saved session: %s", view_file_name.c_str());
    }
}

void reset_session(void)
{
    textview_curses::highlight_map_t &hmap =
        lnav_data.ld_views[LNV_LOG].get_highlights();
    textview_curses::highlight_map_t::iterator hl_iter = hmap.begin();

    log_info("reset session: time=%d", lnav_data.ld_session_time);

    save_session();
    scan_sessions();

    lnav_data.ld_session_time = time(NULL);

    while (hl_iter != hmap.end()) {
        if (hl_iter->first[0] == '$') {
            ++hl_iter;
        }
        else {
            hmap.erase(hl_iter++);
        }
    }

    logfile_sub_source::iterator file_iter;

    for (file_iter = lnav_data.ld_log_source.begin();
         file_iter != lnav_data.ld_log_source.end();
         ++file_iter) {
        logfile *lf             = (*file_iter)->get_file();

        lf->clear_time_offset();
    }

    lnav_data.ld_log_source.clear_min_max_log_times();

    lnav_data.ld_log_source.get_user_bookmark_metadata().clear();

    for (int lpc = 0; lpc < LNV__MAX; lpc++) {
        textview_curses &tc = lnav_data.ld_views[lpc];
        text_sub_source *tss = tc.get_sub_source();

        if (tss == NULL) {
            continue;
        }
        tss->get_filters().clear_filters();
        tss->text_filters_changed();
        tss->text_clear_marks(&textview_curses::BM_USER);
        tc.get_bookmarks()[&textview_curses::BM_USER].clear();
        tss->text_clear_marks(&textview_curses::BM_PARTITION);
        tc.get_bookmarks()[&textview_curses::BM_PARTITION].clear();
        tc.reload_data();
    }
}