Class FileReader

Inheritance Relationships

Base Type

Class Documentation

class FileReader : public mcap::IReadable

IReadable implementation wrapping a FILE* pointer created by fopen() and a read buffer.

Public Functions

FileReader(std::FILE *file)
virtual uint64_t size() const override

Returns the size of the file in bytes.

Returns:

uint64_t The total number of bytes in the MCAP file.

virtual uint64_t read(std::byte **output, uint64_t offset, uint64_t size) override

This method is called by MCAP reader classes when they need to read a portion of the file.

Parameters:

  • output – A pointer to a pointer to the buffer to write to. This method is expected to either maintain an internal buffer, read data into it, and update this pointer to point at the internal buffer, or update this pointer to point directly at the source data if possible. The pointer and data must remain valid and unmodified until the next call to read().

  • offset – The offset in bytes from the beginning of the file to read.

  • size – The number of bytes to read.

Returns:

uint64_t Number of bytes actually read. This may be less than the requested size if the end of the file is reached. The output pointer must be readable from output to output + size. If the read fails, this method should return 0.