C++ (Cpp) OwnedPointerVector::back Examples

Example #1

File: shard_key_pattern.cpp Project: DavidAlphaFox/mongodb

/**
 * Currently the allowable shard keys are either
 * i) a hashed single field, e.g. { a : "hashed" }, or
 * ii) a compound list of ascending, potentially-nested field paths, e.g. { a : 1 , b.c : 1 }
 */
static vector<FieldRef*> parseShardKeyPattern(const BSONObj& keyPattern) {
    OwnedPointerVector<FieldRef> parsedPaths;
    static const vector<FieldRef*> empty;

    BSONObjIterator patternIt(keyPattern);
    while (patternIt.more()) {
        BSONElement patternEl = patternIt.next();
        parsedPaths.push_back(new FieldRef(patternEl.fieldNameStringData()));
        const FieldRef& patternPath = *parsedPaths.back();

        // Empty path
        if (patternPath.numParts() == 0)
            return empty;

        // Extra "." in path?
        if (patternPath.dottedField() != patternEl.fieldNameStringData())
            return empty;

        // Empty parts of the path, ".."?
        for (size_t i = 0; i < patternPath.numParts(); ++i) {
            if (patternPath.getPart(i).size() == 0)
                return empty;
        }

        // Numeric and ascending (1.0), or "hashed" and single field
        if (!patternEl.isNumber()) {
            if (keyPattern.nFields() != 1 || !isHashedPatternEl(patternEl))
                return empty;
        } else if (patternEl.numberInt() != 1) {
            return empty;
        }
    }

    return parsedPaths.release();
}