readRawVarint64

readRawVarint64 is a function typically found in libraries or codebases that deal with data serialization formats like Protocol Buffers or FlatBuffers. Its primary purpose is to decode a 64-bit unsigned integer value that has been encoded using the Varint encoding scheme.

Varint encoding is a variable-length encoding method for integers. It uses fewer bytes for smaller numbers and more bytes for larger numbers, making it efficient for storing data where numbers tend to be small. The most significant bit of each byte is a flag indicating whether the next byte is part of the same varint. If the bit is 1, more bytes follow. If the bit is 0, this is the last byte of the varint.

The readRawVarint64 function reads bytes sequentially from an input stream or buffer. It constructs the 64-bit integer by combining the lower 7 bits of each byte read. The process continues until a byte with the most significant bit set to 0 is encountered, signaling the end of the varint. This method ensures that the original 64-bit integer can be accurately reconstructed. Error handling, such as detecting excessively long varints that could indicate malformed data, is also often included within such functions.