davide
384d907c65
Unmodified source tree of upstream commit 280cb339aa158e099eb936033eecd15719770651
("Merge pull request #389 from SomberNight/202607_release_2_0",
https://github.com/spesmilo/electrumx, release 2.0.0, 3 July 2026).
All Palladium-specific changes are in the commits that follow.
46 lines
1.8 KiB
Plaintext
46 lines
1.8 KiB
Plaintext
Just some notes on performance with Python 3.5. We are taking these into
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account in the code.
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- 60% faster to create lists with [] list comprehensions than tuples
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or lists with tuple(), list(). Of those list is 10% faster than
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tuple.
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- however when not initializing from a generator, a fixed-length tuple
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is at least 80% faster than a list.
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- an implicit default argument is ~5% faster than passing the default
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explicitly
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- using a local variable x rather than self.x in loops and list
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comprehensions is over 50% faster
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- struct.pack, struct.unpack are over 60% faster than int.to_bytes and
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int.from_bytes. They are faster little endian (presumably because
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it matches the host) than big endian regardless of length. Furthermore,
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using stored packing and unpacking methods from Struct classes is faster
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than using the flexible-format struct.[un]pack equivalents.
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After storing the Struct('<Q').unpack_from function as unpack_uint64_from,
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later calls to unpack_uint64_from(b, 0) are about 30% faster than calls to
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unpack_from('<Q', b, 0).
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- single-item list and tuple unpacking. Suppose b = (1, )
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a, = b is a about 0.4% faster than (a,) = b
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and about 45% faster than a = b[0]
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- multiple assignment is faster using tuples only for 3 or more items
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- retrieving a previously stored length of a bytes object can be over 200%
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faster than a new call to len(b)
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- The cpython and pypy stdlibs use a Python-based JSON serializer/deserializer,
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which is stable and easy to use and install, but somewhat slower than
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system-compiled variants. ElectrumX now looks for known popular
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C/Rust-based JSON libraries for Python. If it finds one,
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it's used instead of the stdlib module for improved performance.
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To install a known-compatible system-compiled JSON lib, install ElectrumX
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with the "orjson" extras parameter.
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