private int fillBuffer()

in core/src/main/java/org/apache/james/mime4j/io/MimeBoundaryInputStream.java [218:279]

• 55 lines of code
• 17 McCabe index (conditional complexity)

    private int fillBuffer() throws IOException {
        if (eof) {
            return -1;
        }
        int bytesRead;
        if (!hasData()) {
            bytesRead = buffer.fillBuffer();
            if (bytesRead == -1) {
                eof = true;
            }
        } else {
            bytesRead = 0;
        }

        int i;
        int off = buffer.pos();
        for (;;) {
            i = buffer.indexOf(boundary, off, buffer.limit() - off);
            if (i == -1) {
                break;
            }
            // Make sure the boundary is either at the very beginning of the buffer
            // or preceded with LF
            if (i == buffer.pos() || buffer.byteAt(i - 1) == '\n') {
                int pos = i + boundary.length;
                int remaining = buffer.limit() - pos;
                if (remaining <= 0) {
                    // Make sure the boundary is terminated with EOS
                    break;
                } else {
                    // or with a whitespace or '--'
                    char ch = (char)(buffer.byteAt(pos));
                    if (CharsetUtil.isWhitespace(ch)) {
                        break;
                    }
                    if (ch == '-' && remaining > 1 && (char)(buffer.byteAt(pos+1)) == '-') {
                        break;
                    }
                }
            }
            off = i + boundary.length;
        }
        if (i != -1) {
            limit = i;
            atBoundary = true;
            calculateBoundaryLen();
        } else {
            if (eof) {
                limit = buffer.limit();
            } else {
                int position = buffer.limit() - (boundary.length + 3);    // 2nd position before boundary
                if (position >= 0 && (char) buffer.byteAt(position) == '\r') {
                    limit = buffer.limit() - (boundary.length + 3);
                    // boundary [CR][LF] minus two chars
                } else {
                    limit = buffer.limit() - (boundary.length + 2);
                    // boundary [LF] minus one char
                }
            }
        }
        return bytesRead;
    }