Defined in uproot.compression on line 365.

uproot.compression.decompress(chunk, cursor, context, compressed_bytes, uncompressed_bytes, block_info=None)
  • chunk (uproot.source.chunk.Chunk) – Buffer of contiguous data from the file uproot.source.chunk.Source.

  • cursor (uproot.Cursor) – Current position in that chunk.

  • context (dict) – Auxiliary data used in deserialization.

  • compressed_bytes (int) – Number of compressed bytes to decompress.

  • uncompressed_bytes (int) – Number of uncompressed bytes to expect after decompression.

  • block_info (None or empty list) – List to fill with (compression type class, num compressed bytes, num uncompressed bytes) observed in each compressed block.

Decompresses compressed_bytes of a uproot.source.chunk.Chunk of data, starting at the cursor.

This function parses ROOT’s 9-byte compression headers (17 bytes for LZ4 because it includes a checksum), combining blocks if there are more than one, returning the result as a new uproot.source.chunk.Chunk.