fun readHeader()

in facebook-core/src/main/java/com/facebook/internal/FileLruCache.kt [352:404]
53 lines of code
7 McCabe index (conditional complexity)

    fun readHeader(stream: InputStream): JSONObject? {
      val version = stream.read()
      if (version != HEADER_VERSION) {
        return null
      }
      var headerSize = 0
      repeat(3) {
        val b = stream.read()
        if (b == -1) {
          log(
              LoggingBehavior.CACHE,
              TAG,
              "readHeader: stream.read returned -1 while reading header size")
          return null
        }
        headerSize = headerSize shl 8
        headerSize += b and 0xff
      }
      val headerBytes = ByteArray(headerSize)
      var count = 0
      while (count < headerBytes.size) {
        val readCount = stream.read(headerBytes, count, headerBytes.size - count)
        if (readCount < 1) {
          log(
              LoggingBehavior.CACHE,
              TAG,
              "readHeader: stream.read stopped at " +
                  Integer.valueOf(count) +
                  " when expected " +
                  headerBytes.size)
          return null
        }
        count += readCount
      }
      val headerString = String(headerBytes)
      val header: JSONObject
      val tokener = JSONTokener(headerString)
      header =
          try {
            val parsed = tokener.nextValue()
            if (parsed !is JSONObject) {
              log(
                  LoggingBehavior.CACHE,
                  TAG,
                  "readHeader: expected JSONObject, got " + parsed.javaClass.canonicalName)
              return null
            }
            parsed
          } catch (e: JSONException) {
            throw IOException(e.message)
          }
      return header
    }