866326efe4
Adds utilities for "advanced" methods of compression with lz4 and zstd -- with streaming (a history buffer persisted across messages) and/or precomputed dictionaries. This patch is mostly just glue needed to use the underlying libraries with discontiguous input and output buffers, and for reusing the same compressor context objects across messages. It doesn't contain any innovations of its own. There is one "design decision" in the patch. The block format of LZ4 doesn't contain the length of the compressed blocks. At decompression time, that length must be delivered to the decompressor by a channel separate to the compressed block itself. In `lz4_cstream`, we deal with that by prepending a variable-length integer containing the compressed size to each compressed block. This is suboptimal for single-fragment messages, since the user of lz4_cstream is likely going to remember the length of the whole message anyway, which makes the length prepended to the block redundant. But a loss of 1 byte is probably acceptable for most uses.
Scylla in-source tests.
For details on how to run the tests, see docs/dev/testing.md
Shared C++ utils, libraries are in lib/, for Python - pylib/
alternator - Python tests which connect to a single server and use the DynamoDB API unit, boost, raft - unit tests in C++ cqlpy - Python tests which connect to a single server and use CQL topology* - tests that set up clusters and add/remove nodes cql - approval tests that use CQL and pre-recorded output rest_api - tests for Scylla REST API Port 9000 scylla-gdb - tests for scylla-gdb.py helper script nodetool - tests for C++ implementation of nodetool
If you can use an existing folder, consider adding your test to it. New folders should be used for new large categories/subsystems, or when the test environment is significantly different from some existing suite, e.g. you plan to start scylladb with different configuration, and you intend to add many tests and would like them to reuse an existing Scylla cluster (clusters can be reused for tests within the same folder).
To add a new folder, create a new directory, and then
copy & edit its suite.ini.