blockdevlogger | Line logger

blockdevlogger is a C library. blockdevlogger has no bugs, it has no vulnerabilities, it has a Strong Copyleft License and it has low support. You can download it from GitHub.

Block Device Logger which writes and reads directly to or from a block device (e.g. USB-memory) without using a filesystem. It can also use a fixed size file. BDL tries to minimize the strain on individual parts of a device by using the whole device in a round-robin fashion, with metadata to aid searcing spread around at fixed points. A BDL structure consist of a header at the start of the device which is only written to when first initializing the device. Fixed size blocks of data are then written after this header. A region consists of many blocks (usually 128MB) before ending with a hint block which contains information about where to find the most recent block before it. The hint blocks and other blocks are not pre- initialized, and BDL merely considers any block with invalid checksum to be free space. Backup hint blocks are placed half way inside each region. If a hintblock is corrupt, we attempt to recover the backup. The data blocks have a timestamp and a user defined identifier. When writing a new entry, BDL searches the hint blocks to find unused space. If the device was full, the oldest data block is overwritten, and the rest of this region is also invalidated. The hint blocks are always updated on writes. Timestamp of new entries must be larger than all exisiting entries.