WriteBatch::Reserve

[l0rinc]

Experiment to see the effects of a pre-sized UTXO set write batch.
See related LevelDB PR: google/leveldb#1259

[l0rinc]

Preallocating the string that's used by levelDB batching results in a ~6% faster dump on average:

3546446	8d19012
207429.21	218520.34
208862.11	219388.92
210292.79	220814.04
216711.49	221191.05
217035.96	226861.88
218508.9	234677.65
218530.95	235625.18
219499.49	243075.73
230591.79	245046.15
231249.35	254212.8

Average:

217871.204	231941.374	106.46%

[github-actions]

📊 Benchmark results for this run (13359941665) will be available at: https://bitcoin-dev-tools.github.io/benchcoin/results/pr-136/13359941665/index.html after the github pages "build and deployment" action has completed.
🚀 Speedups: mainnet-default-instrumented: -3.0%, mainnet-large-instrumented: -0.0%, mainnet-default-uninstrumented: -1.5%, mainnet-large-uninstrumented: -0.3%

[github-actions]

📊 Benchmark results for this run (13369809214) will be available at: https://bitcoin-dev-tools.github.io/benchcoin/results/pr-136/13369809214/index.html after the github pages "build and deployment" action has completed.
🚀 Speedups: mainnet-default-instrumented: -8.5%, mainnet-large-instrumented: 2.9%, mainnet-default-uninstrumented: -3.0%, mainnet-large-uninstrumented: 0.1%

[github-actions]

📊 Benchmark results for this run (13391173879) will be available at: https://bitcoin-dev-tools.github.io/benchcoin/results/pr-136/13391173879/index.html after the github pages "build and deployment" action has completed.
🚀 Speedups: mainnet-default-instrumented: -7.5%, mainnet-large-instrumented: -0.3%, mainnet-default-uninstrumented: -2.8%, mainnet-large-uninstrumented: -1.2%

[github-actions]

📊 Benchmark results for this run (13472347706) will be available at: https://bitcoin-dev-tools.github.io/benchcoin/results/pr-136/13472347706/index.html after the github pages "build and deployment" action has completed.
🚀 Speedups: mainnet-default-instrumented: -13.8%, mainnet-large-instrumented: -6.5%, mainnet-default-uninstrumented: -3.6%, mainnet-large-uninstrumented: 1.6%

[github-actions]

📊 Benchmark results for this run (13476270563) will be available at: https://bitcoin-dev-tools.github.io/benchcoin/results/pr-136/13476270563/index.html after the github pages "build and deployment" action has completed.
🚀 Speedups: mainnet-default-instrumented: -16.6%, mainnet-large-instrumented: 2.1%, mainnet-default-uninstrumented: -2.6%, mainnet-large-uninstrumented: 0.2%