SearchUtil.cpp

// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "platform/v8_inspector/SearchUtil.h"

#include "platform/v8_inspector/V8InspectorImpl.h"
#include "platform/v8_inspector/V8InspectorSessionImpl.h"
#include "platform/v8_inspector/V8Regex.h"
#include "platform/v8_inspector/protocol/Protocol.h"

namespace v8_inspector {

namespace {

String16 findMagicComment(const String16& content, const String16& name, bool multiline)
{
    DCHECK(name.find("=") == String16::kNotFound);
    unsigned length = content.length();
    unsigned nameLength = name.length();

    size_t pos = length;
    size_t equalSignPos = 0;
    size_t closingCommentPos = 0;
    while (true) {
        pos = content.reverseFind(name, pos);
        if (pos == String16::kNotFound)
            return String16();

        // Check for a /\/[\/*][@#][ \t]/ regexp (length of 4) before found name.
        if (pos < 4)
            return String16();
        pos -= 4;
        if (content[pos] != '/')
            continue;
        if ((content[pos + 1] != '/' || multiline)
            && (content[pos + 1] != '*' || !multiline))
            continue;
        if (content[pos + 2] != '#' && content[pos + 2] != '@')
            continue;
        if (content[pos + 3] != ' ' && content[pos + 3] != '\t')
            continue;
        equalSignPos = pos + 4 + nameLength;
        if (equalSignPos < length && content[equalSignPos] != '=')
            continue;
        if (multiline) {
            closingCommentPos = content.find("*/", equalSignPos + 1);
            if (closingCommentPos == String16::kNotFound)
                return String16();
        }

        break;
    }

    DCHECK(equalSignPos);
    DCHECK(!multiline || closingCommentPos);
    size_t urlPos = equalSignPos + 1;
    String16 match = multiline
        ? content.substring(urlPos, closingCommentPos - urlPos)
        : content.substring(urlPos);

    size_t newLine = match.find("\n");
    if (newLine != String16::kNotFound)
        match = match.substring(0, newLine);
    match = match.stripWhiteSpace();

    for (unsigned i = 0; i < match.length(); ++i) {
        UChar c = match[i];
        if (c == '"' || c == '\'' || c == ' ' || c == '\t')
            return "";
    }

    return match;
}

String16 createSearchRegexSource(const String16& text)
{
    String16Builder result;

    for (unsigned i = 0; i < text.length(); i++) {
        UChar c = text[i];
        if (c == '[' || c == ']' || c == '(' || c == ')' || c == '{' || c == '}'
            || c == '+' || c == '-' || c == '*' || c == '.' || c == ',' || c == '?'
            || c == '\\' || c == '^' || c == '$' || c == '|') {
            result.append('\\');
        }
        result.append(c);
    }

    return result.toString();
}

std::unique_ptr<std::vector<unsigned>> lineEndings(const String16& text)
{
    std::unique_ptr<std::vector<unsigned>> result(new std::vector<unsigned>());

    const String16 lineEndString = "\n";
    unsigned start = 0;
    while (start < text.length()) {
        size_t lineEnd = text.find(lineEndString, start);
        if (lineEnd == String16::kNotFound)
            break;

        result->push_back(static_cast<unsigned>(lineEnd));
        start = lineEnd + 1;
    }
    result->push_back(static_cast<unsigned>(text.length()));

    return result;
}

std::vector<std::pair<int, String16>> scriptRegexpMatchesByLines(const V8Regex& regex, const String16& text)
{
    std::vector<std::pair<int, String16>> result;
    if (text.isEmpty())
        return result;

    std::unique_ptr<std::vector<unsigned>> endings(lineEndings(text));
    unsigned size = endings->size();
    unsigned start = 0;
    for (unsigned lineNumber = 0; lineNumber < size; ++lineNumber) {
        unsigned lineEnd = endings->at(lineNumber);
        String16 line = text.substring(start, lineEnd - start);
        if (line.length() && line[line.length() - 1] == '\r')
            line = line.substring(0, line.length() - 1);

        int matchLength;
        if (regex.match(line, 0, &matchLength) != -1)
            result.push_back(std::pair<int, String16>(lineNumber, line));

        start = lineEnd + 1;
    }
    return result;
}

std::unique_ptr<protocol::Debugger::SearchMatch> buildObjectForSearchMatch(int lineNumber, const String16& lineContent)
{
    return protocol::Debugger::SearchMatch::create()
        .setLineNumber(lineNumber)
        .setLineContent(lineContent)
        .build();
}

std::unique_ptr<V8Regex> createSearchRegex(V8InspectorImpl* inspector, const String16& query, bool caseSensitive, bool isRegex)
{
    String16 regexSource = isRegex ? query : createSearchRegexSource(query);
    return wrapUnique(new V8Regex(inspector, regexSource, caseSensitive));
}

} // namespace

std::vector<std::unique_ptr<protocol::Debugger::SearchMatch>> searchInTextByLinesImpl(V8InspectorSession* session, const String16& text, const String16& query, const bool caseSensitive, const bool isRegex)
{
    std::unique_ptr<V8Regex> regex = createSearchRegex(static_cast<V8InspectorSessionImpl*>(session)->inspector(), query, caseSensitive, isRegex);
    std::vector<std::pair<int, String16>> matches = scriptRegexpMatchesByLines(*regex.get(), text);

    std::vector<std::unique_ptr<protocol::Debugger::SearchMatch>> result;
    for (const auto& match : matches)
        result.push_back(buildObjectForSearchMatch(match.first, match.second));
    return result;
}

String16 findSourceURL(const String16& content, bool multiline)
{
    return findMagicComment(content, "sourceURL", multiline);
}

String16 findSourceMapURL(const String16& content, bool multiline)
{
    return findMagicComment(content, "sourceMappingURL", multiline);
}

} // namespace v8_inspector