lnav/src/pretty_printer.cc

/**
 * Copyright (c) 2015, 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.
 */

#include "config.h"

#include "pretty_printer.hh"

sig_atomic_t reverse_lookup_enabled = 1;

void sigalrm_handler(int sig)
{
    if (sig == SIGALRM)
    {
        reverse_lookup_enabled = 0;
    }
}

std::string pretty_printer::print() {
    pcre_context_static<30> pc;
    data_token_t dt;

    this->pp_scanner->reset();
    while (this->pp_scanner->tokenize2(pc, dt)) {
        element el(dt, pc);

        switch (dt) {
            case DT_XML_EMPTY_TAG:
                if (is_xml) {
                    this->start_new_line();
                }
                this->pp_values.push_back(el);
                if (is_xml) {
                    this->start_new_line();
                }
                continue;
            case DT_XML_OPEN_TAG:
                if (is_xml) {
                    this->start_new_line();
                    this->write_element(el);
                    this->descend();
                } else {
                    this->pp_values.push_back(el);
                }
                continue;
            case DT_XML_CLOSE_TAG:
                this->flush_values();
                this->ascend();
                this->write_element(el);
                this->start_new_line();
                continue;
            case DT_LCURLY:
            case DT_LSQUARE:
            case DT_LPAREN:
                this->flush_values(true);
                this->pp_values.push_back(el);
                this->descend();
                continue;
            case DT_RCURLY:
            case DT_RSQUARE:
            case DT_RPAREN:
                this->flush_values();
                if (this->pp_body_lines.top()) {
                    this->start_new_line();
                }
                this->ascend();
                this->write_element(el);
                continue;
            case DT_COMMA:
                if (this->pp_depth > 0) {
                    this->flush_values(true);
                    this->write_element(el);
                    this->start_new_line();
                    continue;
                }
                break;
            case DT_WHITE:
                if (this->pp_values.empty() && this->pp_depth == 0) {
                    // this->pp_leading_indent = el.e_capture.length();
                    continue;
                }
                break;
            default:
                break;
        }
        this->pp_values.push_back(el);
    }
    while (this->pp_depth > 0) {
        this->ascend();
    }
    this->flush_values();

    return this->pp_stream.str();
}

void pretty_printer::convert_ip_address(const pretty_printer::element &el) {
    union {
        struct sockaddr_in  sin;
        struct sockaddr_in6 sin6;
    } sa;
    pcre_input &pi = this->pp_scanner->get_input();
    std::string ipstr = pi.get_substr(&el.e_capture);
    std::string result = "unknown";
    char buffer[NI_MAXHOST];
    int socklen, rc;

    if (ipstr == "::") {
        return;
    }

    switch (el.e_token) {
        case DT_IPV4_ADDRESS:
            sa.sin.sin_family = AF_INET;
            rc = inet_pton(AF_INET, ipstr.c_str(), &sa.sin.sin_addr);
            socklen = sizeof(struct sockaddr_in);
            break;
        case DT_IPV6_ADDRESS:
            sa.sin6.sin6_family = AF_INET6;
            rc = inet_pton(AF_INET6, ipstr.c_str(), &sa.sin6.sin6_addr);
            socklen = sizeof(struct sockaddr_in6);
            break;
        default:
            require(0);
            break;
    }
    if (rc == 1 && reverse_lookup_enabled) {
        const struct timeval timeout = {0, 500 * 1000};

        {
            timer::interrupt_timer t(timeout, sigalrm_handler);
            if (t.arm_timer() == 0) {
                rc = getnameinfo((struct sockaddr *)&sa, socklen,
                                 buffer, sizeof(buffer), NULL, 0,
                                 NI_NAMEREQD);
                if (rc == 0) {
                    result = buffer;
                }
            }
            else {
                log_error("Unable to set timer, disabling reverse lookup");
                reverse_lookup_enabled = 0;
            }
        }
        if (!reverse_lookup_enabled) {
            log_info("Reverse lookup in pretty-print view disabled");
        }
    }
    this->pp_stream << " " << ANSI_UNDERLINE_START <<
                    "(" << result << ")" <<
                    ANSI_NORM;
}

void pretty_printer::write_element(const pretty_printer::element &el) {
    if (this->pp_leading_indent == 0 &&
        this->pp_line_length == 0 &&
        el.e_token == DT_WHITE) {
        return;
    }
    if (this->pp_line_length == 0 && el.e_token == DT_LINE) {
        return;
    }
    pcre_input &pi = this->pp_scanner->get_input();
    if (this->pp_line_length == 0) {
        this->append_indent();
    }
    if (el.e_token == DT_QUOTED_STRING) {
        auto_mem<char> unquoted_str((char *)malloc(el.e_capture.length() + 1));
        const char *start = pi.get_substr_start(&el.e_capture);
        unquote(unquoted_str.in(), start, el.e_capture.length());
        data_scanner ds(unquoted_str.in());
        pretty_printer str_pp(&ds,
                              this->pp_leading_indent + this->pp_depth * 4);
        std::string result = str_pp.print();
        if (result.find('\n') != std::string::npos) {
            switch (start[0]) {
                case 'r':
                case 'u':
                    this->pp_stream << start[0];
                    this->pp_stream << start[1] << start[1];
                    break;
                default:
                    this->pp_stream << start[0] << start[0];
                    break;
            }
            this->pp_stream
                << std::endl
                << result;
            if (!endswith(result.c_str(), "\n")) {
                this->pp_stream << std::endl;
            }
            this->pp_stream
                << start[el.e_capture.length() - 1]
                << start[el.e_capture.length() - 1];
        } else {
            this->pp_stream << pi.get_substr(&el.e_capture);
        }
    } else {
        this->pp_stream << pi.get_substr(&el.e_capture);
        switch (el.e_token) {
            case DT_IPV4_ADDRESS:
            case DT_IPV6_ADDRESS:
                this->convert_ip_address(el);
                break;
            default:
                break;
        }
    }
    this->pp_line_length += el.e_capture.length();
    if (el.e_token == DT_LINE) {
        this->pp_line_length = 0;
        this->pp_body_lines.top() += 1;
    }
}

void pretty_printer::append_indent() {
    this->pp_stream << std::string(this->pp_leading_indent, ' ');
    if (this->pp_stream.tellp() == this->pp_leading_indent) {
        return;
    }
    for (int lpc = 0; lpc < this->pp_depth; lpc++) {
        this->pp_stream << "    ";
    }
}

bool pretty_printer::flush_values(bool start_on_depth) {
    bool retval = false;

    while (!this->pp_values.empty()) {
        {
            element &el = this->pp_values.front();
            this->write_element(this->pp_values.front());
            if (start_on_depth &&
                (el.e_token == DT_LSQUARE ||
                 el.e_token == DT_LCURLY)) {
                if (this->pp_line_length > 0) {
                    this->pp_stream << std::endl;
                }
                this->pp_line_length = 0;
            }
        }
        this->pp_values.pop_front();
        retval = true;
    }
    return retval;
}

void pretty_printer::start_new_line() {
    bool has_output;

    if (this->pp_line_length > 0) {
        this->pp_stream << std::endl;
        this->pp_line_length = 0;
    }
    has_output = this->flush_values();
    if (has_output && this->pp_line_length > 0) {
        this->pp_stream << std::endl;
    }
    this->pp_line_length = 0;
    this->pp_body_lines.top() += 1;
}

void pretty_printer::ascend() {
    if (this->pp_depth > 0) {
        int lines = this->pp_body_lines.top();
        this->pp_depth -= 1;
        this->pp_body_lines.pop();
        this->pp_body_lines.top() += lines;
    }
    else {
        this->pp_body_lines.top() = 0;
    }
}

void pretty_printer::descend() {
    this->pp_depth += 1;
    this->pp_body_lines.push(0);
}