mercurial/branchmap.py
author Pierre-Yves David <pierre-yves.david@octobus.net>
Sat, 25 Apr 2020 12:37:46 +0200
changeset 46151 c6bc77f7e593
parent 45942 89a2afe31e82
child 46254 c4b792fa109e
permissions -rw-r--r--
copies-rust: tokenize all paths into integer Copy information for each changesets tend to affect a small new number of path. However, each of these path might be handled a large number of time. Handling HgPathBuf (aka `Vec<u8>`) is expensive. Handling integer is cheap. With this patch we: - turn any input path into an integer "token" early, - do all the internal logic using such "token", - turn "token" back into path right before returning a result. This gives use a quite significant performance boost in our slower cases. Repo Case Source-Rev Dest-Rev # of revisions old time new time Difference Factor time per rev --------------------------------------------------------------------------------------------------------------------------------------------------------------- pypy x000_revs_x000_added_x_copies 8a3b5bfd266e 2c68e87c3efe : 6780 revs, 0.092828 s, 0.081225 s, -0.011603 s, × 0.8750, 11 µs/rev pypy x0000_revs_x_added_0_copies d1defd0dc478 c9cb1334cc78 : 43645 revs, 0.711975 s, 0.586011 s, -0.125964 s, × 0.8231, 13 µs/rev pypy x0000_revs_xx000_added_x000_copies 08ea3258278e d9fa043f30c0 : 11316 revs, 0.124505 s, 0.114173 s, -0.010332 s, × 0.9170, 10 µs/rev netbeans x000_revs_x000_added_x000_copies ff453e9fee32 411350406ec2 : 5750 revs, 0.072072 s, 0.061004 s, -0.011068 s, × 0.8464, 10 µs/rev netbeans x0000_revs_xx000_added_x000_copies 588c2d1ced70 1aad62e59ddd : 66949 revs, 0.682732 s, 0.535874 s, -0.146858 s, × 0.7849, 8 µs/rev mozilla-central x00000_revs_x0000_added_x0000_copies 6832ae71433c 4c222a1d9a00 : 153721 revs, 1.935918 s, 1.781383 s, -0.154535 s, × 0.9202, 11 µs/rev mozilla-central x00000_revs_x00000_added_x000_copies 76caed42cf7c 1daa622bbe42 : 204976 revs, 2.827320 s, 2.603867 s, -0.223453 s, × 0.9210, 12 µs/rev mozilla-try x0000_revs_xx000_added_x000_copies 89294cd501d9 7ccb2fc7ccb5 : 97052 revs, 3.243010 s, 1.529120 s, -1.713890 s, × 0.4715, 15 µs/rev mozilla-try x00000_revs_x_added_0_copies 6a320851d377 1ebb79acd503 : 363753 revs, 5.693818 s, 4.842699 s, -0.851119 s, × 0.8505, 13 µs/rev mozilla-try x00000_revs_x_added_x_copies 5173c4b6f97c 95d83ee7242d : 362229 revs, 5.677655 s, 4.761732 s, -0.915923 s, × 0.8387, 13 µs/rev mozilla-try x00000_revs_x000_added_x_copies 9126823d0e9c ca82787bb23c : 359344 revs, 5.563370 s, 4.733912 s, -0.829458 s, × 0.8509, 13 µs/rev mozilla-try x00000_revs_x0000_added_x0000_copies 8d3fafa80d4b eb884023b810 : 192665 revs, 2.864099 s, 2.593410 s, -0.270689 s, × 0.9055, 13 µs/rev mozilla-try x00000_revs_x00000_added_x0000_copies 1b661134e2ca 1ae03d022d6d : 228985 revs, 113.297287 s, 41.041198 s, -72.256089 s, × 0.3622, 179 µs/rev mozilla-try x00000_revs_x00000_added_x000_copies 9b2a99adc05e 8e29777b48e6 : 382065 revs, 59.498652 s, 27.915689 s, -31.582963 s, × 0.4692, 73 µs/rev Full timing comparison between this revision and the previous one: Repo Case Source-Rev Dest-Rev # of revisions old time new time Difference Factor time per rev --------------------------------------------------------------------------------------------------------------------------------------------------------------- mercurial x_revs_x_added_0_copies ad6b123de1c7 39cfcef4f463 : 1 revs, 0.000042 s, 0.000042 s, +0.000000 s, × 1.0000, 42 µs/rev mercurial x_revs_x_added_x_copies 2b1c78674230 0c1d10351869 : 6 revs, 0.000104 s, 0.000110 s, +0.000006 s, × 1.0577, 18 µs/rev mercurial x000_revs_x000_added_x_copies 81f8ff2a9bf2 dd3267698d84 : 1032 revs, 0.004913 s, 0.004918 s, +0.000005 s, × 1.0010, 4 µs/rev pypy x_revs_x_added_0_copies aed021ee8ae8 099ed31b181b : 9 revs, 0.000191 s, 0.000195 s, +0.000004 s, × 1.0209, 21 µs/rev pypy x_revs_x000_added_0_copies 4aa4e1f8e19a 359343b9ac0e : 1 revs, 0.000050 s, 0.000049 s, -0.000001 s, × 0.9800, 49 µs/rev pypy x_revs_x_added_x_copies ac52eb7bbbb0 72e022663155 : 7 revs, 0.000112 s, 0.000112 s, +0.000000 s, × 1.0000, 16 µs/rev pypy x_revs_x00_added_x_copies c3b14617fbd7 ace7255d9a26 : 1 revs, 0.000288 s, 0.000324 s, +0.000036 s, × 1.1250, 324 µs/rev pypy x_revs_x000_added_x000_copies df6f7a526b60 a83dc6a2d56f : 6 revs, 0.010411 s, 0.010611 s, +0.000200 s, × 1.0192, 1768 µs/rev pypy x000_revs_xx00_added_0_copies 89a76aede314 2f22446ff07e : 4785 revs, 0.052852 s, 0.050835 s, -0.002017 s, × 0.9618, 10 µs/rev pypy x000_revs_x000_added_x_copies 8a3b5bfd266e 2c68e87c3efe : 6780 revs, 0.092828 s, 0.081225 s, -0.011603 s, × 0.8750, 11 µs/rev pypy x000_revs_x000_added_x000_copies 89a76aede314 7b3dda341c84 : 5441 revs, 0.063269 s, 0.061291 s, -0.001978 s, × 0.9687, 11 µs/rev pypy x0000_revs_x_added_0_copies d1defd0dc478 c9cb1334cc78 : 43645 revs, 0.711975 s, 0.586011 s, -0.125964 s, × 0.8231, 13 µs/rev pypy x0000_revs_xx000_added_0_copies bf2c629d0071 4ffed77c095c : 2 revs, 0.012771 s, 0.012824 s, +0.000053 s, × 1.0042, 6412 µs/rev pypy x0000_revs_xx000_added_x000_copies 08ea3258278e d9fa043f30c0 : 11316 revs, 0.124505 s, 0.114173 s, -0.010332 s, × 0.9170, 10 µs/rev netbeans x_revs_x_added_0_copies fb0955ffcbcd a01e9239f9e7 : 2 revs, 0.000082 s, 0.000085 s, +0.000003 s, × 1.0366, 42 µs/rev netbeans x_revs_x000_added_0_copies 6f360122949f 20eb231cc7d0 : 2 revs, 0.000111 s, 0.000108 s, -0.000003 s, × 0.9730, 54 µs/rev netbeans x_revs_x_added_x_copies 1ada3faf6fb6 5a39d12eecf4 : 3 revs, 0.000171 s, 0.000175 s, +0.000004 s, × 1.0234, 58 µs/rev netbeans x_revs_x00_added_x_copies 35be93ba1e2c 9eec5e90c05f : 9 revs, 0.000708 s, 0.000719 s, +0.000011 s, × 1.0155, 79 µs/rev netbeans x000_revs_xx00_added_0_copies eac3045b4fdd 51d4ae7f1290 : 1421 revs, 0.010608 s, 0.010175 s, -0.000433 s, × 0.9592, 7 µs/rev netbeans x000_revs_x000_added_x_copies e2063d266acd 6081d72689dc : 1533 revs, 0.015635 s, 0.015569 s, -0.000066 s, × 0.9958, 10 µs/rev netbeans x000_revs_x000_added_x000_copies ff453e9fee32 411350406ec2 : 5750 revs, 0.072072 s, 0.061004 s, -0.011068 s, × 0.8464, 10 µs/rev netbeans x0000_revs_xx000_added_x000_copies 588c2d1ced70 1aad62e59ddd : 66949 revs, 0.682732 s, 0.535874 s, -0.146858 s, × 0.7849, 8 µs/rev mozilla-central x_revs_x_added_0_copies 3697f962bb7b 7015fcdd43a2 : 2 revs, 0.000090 s, 0.000090 s, +0.000000 s, × 1.0000, 45 µs/rev mozilla-central x_revs_x000_added_0_copies dd390860c6c9 40d0c5bed75d : 8 revs, 0.000210 s, 0.000281 s, +0.000071 s, × 1.3381, 35 µs/rev mozilla-central x_revs_x_added_x_copies 8d198483ae3b 14207ffc2b2f : 9 revs, 0.000182 s, 0.000187 s, +0.000005 s, × 1.0275, 20 µs/rev mozilla-central x_revs_x00_added_x_copies 98cbc58cc6bc 446a150332c3 : 7 revs, 0.000594 s, 0.000660 s, +0.000066 s, × 1.1111, 94 µs/rev mozilla-central x_revs_x000_added_x000_copies 3c684b4b8f68 0a5e72d1b479 : 3 revs, 0.003102 s, 0.003385 s, +0.000283 s, × 1.0912, 1128 µs/rev mozilla-central x_revs_x0000_added_x0000_copies effb563bb7e5 c07a39dc4e80 : 6 revs, 0.060234 s, 0.069812 s, +0.009578 s, × 1.1590, 11635 µs/rev mozilla-central x000_revs_xx00_added_0_copies 6100d773079a 04a55431795e : 1593 revs, 0.006300 s, 0.006503 s, +0.000203 s, × 1.0322, 4 µs/rev mozilla-central x000_revs_x000_added_x_copies 9f17a6fc04f9 2d37b966abed : 41 revs, 0.004817 s, 0.004988 s, +0.000171 s, × 1.0355, 121 µs/rev mozilla-central x000_revs_x000_added_x000_copies 7c97034feb78 4407bd0c6330 : 7839 revs, 0.065451 s, 0.063963 s, -0.001488 s, × 0.9773, 8 µs/rev mozilla-central x0000_revs_xx000_added_0_copies 9eec5917337d 67118cc6dcad : 615 revs, 0.026282 s, 0.026225 s, -0.000057 s, × 0.9978, 42 µs/rev mozilla-central x0000_revs_xx000_added_x000_copies f78c615a656c 96a38b690156 : 30263 revs, 0.206873 s, 0.201377 s, -0.005496 s, × 0.9734, 6 µs/rev mozilla-central x00000_revs_x0000_added_x0000_copies 6832ae71433c 4c222a1d9a00 : 153721 revs, 1.935918 s, 1.781383 s, -0.154535 s, × 0.9202, 11 µs/rev mozilla-central x00000_revs_x00000_added_x000_copies 76caed42cf7c 1daa622bbe42 : 204976 revs, 2.827320 s, 2.603867 s, -0.223453 s, × 0.9210, 12 µs/rev mozilla-try x_revs_x_added_0_copies aaf6dde0deb8 9790f499805a : 2 revs, 0.000842 s, 0.000845 s, +0.000003 s, × 1.0036, 422 µs/rev mozilla-try x_revs_x000_added_0_copies d8d0222927b4 5bb8ce8c7450 : 2 revs, 0.000870 s, 0.000862 s, -0.000008 s, × 0.9908, 431 µs/rev mozilla-try x_revs_x_added_x_copies 092fcca11bdb 936255a0384a : 4 revs, 0.000165 s, 0.000161 s, -0.000004 s, × 0.9758, 40 µs/rev mozilla-try x_revs_x00_added_x_copies b53d2fadbdb5 017afae788ec : 2 revs, 0.001145 s, 0.001163 s, +0.000018 s, × 1.0157, 581 µs/rev mozilla-try x_revs_x000_added_x000_copies 20408ad61ce5 6f0ee96e21ad : 1 revs, 0.026500 s, 0.032414 s, +0.005914 s, × 1.2232, 32414 µs/rev mozilla-try x_revs_x0000_added_x0000_copies effb563bb7e5 c07a39dc4e80 : 6 revs, 0.059407 s, 0.070149 s, +0.010742 s, × 1.1808, 11691 µs/rev mozilla-try x000_revs_xx00_added_0_copies 6100d773079a 04a55431795e : 1593 revs, 0.006325 s, 0.006526 s, +0.000201 s, × 1.0318, 4 µs/rev mozilla-try x000_revs_x000_added_x_copies 9f17a6fc04f9 2d37b966abed : 41 revs, 0.005171 s, 0.005187 s, +0.000016 s, × 1.0031, 126 µs/rev mozilla-try x000_revs_x000_added_x000_copies 1346fd0130e4 4c65cbdabc1f : 6657 revs, 0.066837 s, 0.065047 s, -0.001790 s, × 0.9732, 9 µs/rev mozilla-try x0000_revs_x_added_0_copies 63519bfd42ee a36a2a865d92 : 40314 revs, 0.314252 s, 0.301129 s, -0.013123 s, × 0.9582, 7 µs/rev mozilla-try x0000_revs_x_added_x_copies 9fe69ff0762d bcabf2a78927 : 38690 revs, 0.304160 s, 0.280683 s, -0.023477 s, × 0.9228, 7 µs/rev mozilla-try x0000_revs_xx000_added_x_copies 156f6e2674f2 4d0f2c178e66 : 8598 revs, 0.089223 s, 0.084897 s, -0.004326 s, × 0.9515, 9 µs/rev mozilla-try x0000_revs_xx000_added_0_copies 9eec5917337d 67118cc6dcad : 615 revs, 0.026711 s, 0.026620 s, -0.000091 s, × 0.9966, 43 µs/rev mozilla-try x0000_revs_xx000_added_x000_copies 89294cd501d9 7ccb2fc7ccb5 : 97052 revs, 3.243010 s, 1.529120 s, -1.713890 s, × 0.4715, 15 µs/rev mozilla-try x0000_revs_x0000_added_x0000_copies e928c65095ed e951f4ad123a : 52031 revs, 0.756500 s, 0.738709 s, -0.017791 s, × 0.9765, 14 µs/rev mozilla-try x00000_revs_x_added_0_copies 6a320851d377 1ebb79acd503 : 363753 revs, 5.693818 s, 4.842699 s, -0.851119 s, × 0.8505, 13 µs/rev mozilla-try x00000_revs_x00000_added_0_copies dc8a3ca7010e d16fde900c9c : 34414 revs, 0.590904 s, 0.596946 s, +0.006042 s, × 1.0102, 17 µs/rev mozilla-try x00000_revs_x_added_x_copies 5173c4b6f97c 95d83ee7242d : 362229 revs, 5.677655 s, 4.761732 s, -0.915923 s, × 0.8387, 13 µs/rev mozilla-try x00000_revs_x000_added_x_copies 9126823d0e9c ca82787bb23c : 359344 revs, 5.563370 s, 4.733912 s, -0.829458 s, × 0.8509, 13 µs/rev mozilla-try x00000_revs_x0000_added_x0000_copies 8d3fafa80d4b eb884023b810 : 192665 revs, 2.864099 s, 2.593410 s, -0.270689 s, × 0.9055, 13 µs/rev mozilla-try x00000_revs_x00000_added_x0000_copies 1b661134e2ca 1ae03d022d6d : 228985 revs, 113.297287 s, 41.041198 s, -72.256089 s, × 0.3622, 179 µs/rev mozilla-try x00000_revs_x00000_added_x000_copies 9b2a99adc05e 8e29777b48e6 : 382065 revs, 59.498652 s, 27.915689 s, -31.582963 s, × 0.4692, 73 µs/rev Full timing comparison between this revision and the filelog copy tracing. Repo Case Source-Rev Dest-Rev # of revisions filelog sidedata Difference Factor time per rev --------------------------------------------------------------------------------------------------------------------------------------------------------------- mercurial x_revs_x_added_0_copies ad6b123de1c7 39cfcef4f463 : 1 revs, 0.000903 s, 0.000042 s, -0.000861 s, × 0.0465, 41 µs/rev mercurial x_revs_x_added_x_copies 2b1c78674230 0c1d10351869 : 6 revs, 0.001861 s, 0.000110 s, -0.001751 s, × 0.0591, 18 µs/rev mercurial x000_revs_x000_added_x_copies 81f8ff2a9bf2 dd3267698d84 : 1032 revs, 0.018577 s, 0.004918 s, -0.013659 s, × 0.2647, 4 µs/rev pypy x_revs_x_added_0_copies aed021ee8ae8 099ed31b181b : 9 revs, 0.001519 s, 0.000195 s, -0.001324 s, × 0.1283, 21 µs/rev pypy x_revs_x000_added_0_copies 4aa4e1f8e19a 359343b9ac0e : 1 revs, 0.213855 s, 0.000049 s, -0.350d73 s, × 0.0002, 48 µs/rev pypy x_revs_x_added_x_copies ac52eb7bbbb0 72e022663155 : 7 revs, 0.017022 s, 0.000112 s, -0.016910 s, × 0.0065, 15 µs/rev pypy x_revs_x00_added_x_copies c3b14617fbd7 ace7255d9a26 : 1 revs, 0.019398 s, 0.000324 s, -0.019074 s, × 0.0167, 323 µs/rev pypy x_revs_x000_added_x000_copies df6f7a526b60 a83dc6a2d56f : 6 revs, 0.769467 s, 0.010611 s, -0.758856 s, × 0.0137, 1768 µs/rev pypy x000_revs_xx00_added_0_copies 89a76aede314 2f22446ff07e : 4785 revs, 1.221952 s, 0.050835 s, -1.171117 s, × 0.0416, 10 µs/rev pypy x000_revs_x000_added_x_copies 8a3b5bfd266e 2c68e87c3efe : 6780 revs, 1.304007 s, 0.081225 s, -1.222782 s, × 0.0622, 11 µs/rev pypy x000_revs_x000_added_x000_copies 89a76aede314 7b3dda341c84 : 5441 revs, 1.686610 s, 0.061291 s, -1.625319 s, × 0.0363, 11 µs/rev pypy x0000_revs_x_added_0_copies d1defd0dc478 c9cb1334cc78 : 43645 revs, 0.001107 s, 0.586011 s, +0.584904 s, × 529.36, 13 µs/rev pypy x0000_revs_xx000_added_0_copies bf2c629d0071 4ffed77c095c : 2 revs, 1.100760 s, 0.012824 s, -1.087936 s, × 0.0116, 6408 µs/rev pypy x0000_revs_xx000_added_x000_copies 08ea3258278e d9fa043f30c0 : 11316 revs, 1.350547 s, 0.114173 s, -1.236374 s, × 0.0845, 10 µs/rev netbeans x_revs_x_added_0_copies fb0955ffcbcd a01e9239f9e7 : 2 revs, 0.027864 s, 0.000085 s, -0.027779 s, × 0.0030, 42 µs/rev netbeans x_revs_x000_added_0_copies 6f360122949f 20eb231cc7d0 : 2 revs, 0.132479 s, 0.000108 s, -0.132371 s, × 0.0008, 53 µs/rev netbeans x_revs_x_added_x_copies 1ada3faf6fb6 5a39d12eecf4 : 3 revs, 0.025405 s, 0.000175 s, -0.025230 s, × 0.0068, 58 µs/rev netbeans x_revs_x00_added_x_copies 35be93ba1e2c 9eec5e90c05f : 9 revs, 0.053244 s, 0.000719 s, -0.052525 s, × 0.0135, 79 µs/rev netbeans x000_revs_xx00_added_0_copies eac3045b4fdd 51d4ae7f1290 : 1421 revs, 0.038017 s, 0.010175 s, -0.027842 s, × 0.2676, 7 µs/rev netbeans x000_revs_x000_added_x_copies e2063d266acd 6081d72689dc : 1533 revs, 0.198308 s, 0.015569 s, -0.182739 s, × 0.0785, 10 µs/rev netbeans x000_revs_x000_added_x000_copies ff453e9fee32 411350406ec2 : 5750 revs, 0.949749 s, 0.061004 s, -0.888745 s, × 0.0642, 10 µs/rev netbeans x0000_revs_xx000_added_x000_copies 588c2d1ced70 1aad62e59ddd : 66949 revs, 3.932262 s, 0.535874 s, -3.396388 s, × 0.1362, 8 µs/rev mozilla-central x_revs_x_added_0_copies 3697f962bb7b 7015fcdd43a2 : 2 revs, 0.024490 s, 0.000090 s, -0.024400 s, × 0.0036, 44 µs/rev mozilla-central x_revs_x000_added_0_copies dd390860c6c9 40d0c5bed75d : 8 revs, 0.143885 s, 0.000281 s, -0.143604 s, × 0.0019, 35 µs/rev mozilla-central x_revs_x_added_x_copies 8d198483ae3b 14207ffc2b2f : 9 revs, 0.025471 s, 0.000187 s, -0.025284 s, × 0.0073, 20 µs/rev mozilla-central x_revs_x00_added_x_copies 98cbc58cc6bc 446a150332c3 : 7 revs, 0.086013 s, 0.000660 s, -0.085353 s, × 0.0076, 94 µs/rev mozilla-central x_revs_x000_added_x000_copies 3c684b4b8f68 0a5e72d1b479 : 3 revs, 0.200726 s, 0.003385 s, -0.197341 s, × 0.0168, 1127 µs/rev mozilla-central x_revs_x0000_added_x0000_copies effb563bb7e5 c07a39dc4e80 : 6 revs, 2.224171 s, 0.069812 s, -2.154359 s, × 0.0313, 11633 µs/rev mozilla-central x000_revs_xx00_added_0_copies 6100d773079a 04a55431795e : 1593 revs, 0.090780 s, 0.006503 s, -0.084277 s, × 0.0716, 4 µs/rev mozilla-central x000_revs_x000_added_x_copies 9f17a6fc04f9 2d37b966abed : 41 revs, 0.764805 s, 0.004988 s, -0.759817 s, × 0.0065, 121 µs/rev mozilla-central x000_revs_x000_added_x000_copies 7c97034feb78 4407bd0c6330 : 7839 revs, 1.161405 s, 0.063963 s, -1.097442 s, × 0.0550, 8 µs/rev mozilla-central x0000_revs_xx000_added_0_copies 9eec5917337d 67118cc6dcad : 615 revs, 6.816186 s, 0.026225 s, -6.789961 s, × 0.0038, 42 µs/rev mozilla-central x0000_revs_xx000_added_x000_copies f78c615a656c 96a38b690156 : 30263 revs, 3.374819 s, 0.201377 s, -3.173442 s, × 0.0596, 6 µs/rev mozilla-central x00000_revs_x0000_added_x0000_copies 6832ae71433c 4c222a1d9a00 : 153721 revs, 16.285469 s, 1.781383 s, -14.504086 s, × 0.1093, 11 µs/rev mozilla-central x00000_revs_x00000_added_x000_copies 76caed42cf7c 1daa622bbe42 : 204976 revs, 21.207733 s, 2.603867 s, -18.603866 s, × 0.1227, 12 µs/rev mozilla-try x_revs_x_added_0_copies aaf6dde0deb8 9790f499805a : 2 revs, 0.080843 s, 0.000845 s, -0.079998 s, × 0.0104, 422 µs/rev mozilla-try x_revs_x000_added_0_copies d8d0222927b4 5bb8ce8c7450 : 2 revs, 0.511068 s, 0.000862 s, -0.510206 s, × 0.0016, 430 µs/rev mozilla-try x_revs_x_added_x_copies 092fcca11bdb 936255a0384a : 4 revs, 0.021573 s, 0.000161 s, -0.021412 s, × 0.0074, 40 µs/rev mozilla-try x_revs_x00_added_x_copies b53d2fadbdb5 017afae788ec : 2 revs, 0.227726 s, 0.001163 s, -0.226563 s, × 0.0051, 581 µs/rev mozilla-try x_revs_x000_added_x000_copies 20408ad61ce5 6f0ee96e21ad : 1 revs, 1.120448 s, 0.032414 s, -1.088034 s, × 0.0289, 32381 µs/rev mozilla-try x_revs_x0000_added_x0000_copies effb563bb7e5 c07a39dc4e80 : 6 revs, 2.241713 s, 0.070149 s, -2.171564 s, × 0.0312, 11689 µs/rev mozilla-try x000_revs_xx00_added_0_copies 6100d773079a 04a55431795e : 1593 revs, 0.090633 s, 0.006526 s, -0.084107 s, × 0.0720, 4 µs/rev mozilla-try x000_revs_x000_added_x_copies 9f17a6fc04f9 2d37b966abed : 41 revs, 0.770403 s, 0.005187 s, -0.765216 s, × 0.0067, 126 µs/rev mozilla-try x000_revs_x000_added_x000_copies 1346fd0130e4 4c65cbdabc1f : 6657 revs, 1.184557 s, 0.065047 s, -1.119510 s, × 0.0549, 9 µs/rev mozilla-try x0000_revs_x_added_0_copies 63519bfd42ee a36a2a865d92 : 40314 revs, 0.085790 s, 0.301129 s, +0.215339 s, × 3.5100, 7 µs/rev mozilla-try x0000_revs_x_added_x_copies 9fe69ff0762d bcabf2a78927 : 38690 revs, 0.080616 s, 0.280683 s, +0.200067 s, × 3.4817, 7 µs/rev mozilla-try x0000_revs_xx000_added_x_copies 156f6e2674f2 4d0f2c178e66 : 8598 revs, 7.712554 s, 0.084897 s, -7.627657 s, × 0.0110, 9 µs/rev mozilla-try x0000_revs_xx000_added_0_copies 9eec5917337d 67118cc6dcad : 615 revs, 6.937294 s, 0.026620 s, -6.910674 s, × 0.0038, 43 µs/rev mozilla-try x0000_revs_xx000_added_x000_copies 89294cd501d9 7ccb2fc7ccb5 : 97052 revs, 7.712313 s, 1.529120 s, -6.183193 s, × 0.1982, 15 µs/rev mozilla-try x0000_revs_x0000_added_x0000_copies e928c65095ed e951f4ad123a : 52031 revs, 9.966910 s, 0.738709 s, -9.228201 s, × 0.0741, 14 µs/rev mozilla-try x00000_revs_x_added_0_copies 6a320851d377 1ebb79acd503 : 363753 revs, 0.090397 s, 4.842699 s, +4.752302 s, × 53.571, 13 µs/rev mozilla-try x00000_revs_x00000_added_0_copies dc8a3ca7010e d16fde900c9c : 34414 revs, 27.817167 s, 0.596946 s, -27.220221 s, × 0.0214, 17 µs/rev mozilla-try x00000_revs_x_added_x_copies 5173c4b6f97c 95d83ee7242d : 362229 revs, 0.091305 s, 4.761732 s, +4.670427 s, × 52.151, 13 µs/rev mozilla-try x00000_revs_x000_added_x_copies 9126823d0e9c ca82787bb23c : 359344 revs, 0.231183 s, 4.733912 s, +4.502729 s, × 20.476, 13 µs/rev mozilla-try x00000_revs_x0000_added_x0000_copies 8d3fafa80d4b eb884023b810 : 192665 revs, 19.830617 s, 2.593410 s, -17.237207 s, × 0.1307, 13 µs/rev mozilla-try x00000_revs_x00000_added_x0000_copies 1b661134e2ca 1ae03d022d6d : 228985 revs, 21.743873 s, 41.041198 s, +19.297325 s, × 1.8874, 179 µs/rev mozilla-try x00000_revs_x00000_added_x000_copies 9b2a99adc05e 8e29777b48e6 : 382065 revs, 25.935037 s, 27.915689 s, +1.980652 s, × 1.0763, 73 µs/rev Differential Revision: https://phab.mercurial-scm.org/D9493

# branchmap.py - logic to computes, maintain and stores branchmap for local repo
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import struct

from .node import (
    bin,
    hex,
    nullid,
    nullrev,
)
from . import (
    encoding,
    error,
    pycompat,
    scmutil,
    util,
)
from .utils import (
    repoviewutil,
    stringutil,
)

if pycompat.TYPE_CHECKING:
    from typing import (
        Any,
        Callable,
        Dict,
        Iterable,
        List,
        Optional,
        Set,
        Tuple,
        Union,
    )

    assert any(
        (
            Any,
            Callable,
            Dict,
            Iterable,
            List,
            Optional,
            Set,
            Tuple,
            Union,
        )
    )

subsettable = repoviewutil.subsettable

calcsize = struct.calcsize
pack_into = struct.pack_into
unpack_from = struct.unpack_from


class BranchMapCache(object):
    """mapping of filtered views of repo with their branchcache"""

    def __init__(self):
        self._per_filter = {}

    def __getitem__(self, repo):
        self.updatecache(repo)
        return self._per_filter[repo.filtername]

    def updatecache(self, repo):
        """Update the cache for the given filtered view on a repository"""
        # This can trigger updates for the caches for subsets of the filtered
        # view, e.g. when there is no cache for this filtered view or the cache
        # is stale.

        cl = repo.changelog
        filtername = repo.filtername
        bcache = self._per_filter.get(filtername)
        if bcache is None or not bcache.validfor(repo):
            # cache object missing or cache object stale? Read from disk
            bcache = branchcache.fromfile(repo)

        revs = []
        if bcache is None:
            # no (fresh) cache available anymore, perhaps we can re-use
            # the cache for a subset, then extend that to add info on missing
            # revisions.
            subsetname = subsettable.get(filtername)
            if subsetname is not None:
                subset = repo.filtered(subsetname)
                bcache = self[subset].copy()
                extrarevs = subset.changelog.filteredrevs - cl.filteredrevs
                revs.extend(r for r in extrarevs if r <= bcache.tiprev)
            else:
                # nothing to fall back on, start empty.
                bcache = branchcache()

        revs.extend(cl.revs(start=bcache.tiprev + 1))
        if revs:
            bcache.update(repo, revs)

        assert bcache.validfor(repo), filtername
        self._per_filter[repo.filtername] = bcache

    def replace(self, repo, remotebranchmap):
        """Replace the branchmap cache for a repo with a branch mapping.

        This is likely only called during clone with a branch map from a
        remote.

        """
        cl = repo.changelog
        clrev = cl.rev
        clbranchinfo = cl.branchinfo
        rbheads = []
        closed = set()
        for bheads in pycompat.itervalues(remotebranchmap):
            rbheads += bheads
            for h in bheads:
                r = clrev(h)
                b, c = clbranchinfo(r)
                if c:
                    closed.add(h)

        if rbheads:
            rtiprev = max((int(clrev(node)) for node in rbheads))
            cache = branchcache(
                remotebranchmap,
                repo[rtiprev].node(),
                rtiprev,
                closednodes=closed,
            )

            # Try to stick it as low as possible
            # filter above served are unlikely to be fetch from a clone
            for candidate in (b'base', b'immutable', b'served'):
                rview = repo.filtered(candidate)
                if cache.validfor(rview):
                    self._per_filter[candidate] = cache
                    cache.write(rview)
                    return

    def clear(self):
        self._per_filter.clear()


def _unknownnode(node):
    """raises ValueError when branchcache found a node which does not exists"""
    raise ValueError('node %s does not exist' % pycompat.sysstr(hex(node)))


def _branchcachedesc(repo):
    if repo.filtername is not None:
        return b'branch cache (%s)' % repo.filtername
    else:
        return b'branch cache'


class branchcache(object):
    """A dict like object that hold branches heads cache.

    This cache is used to avoid costly computations to determine all the
    branch heads of a repo.

    The cache is serialized on disk in the following format:

    <tip hex node> <tip rev number> [optional filtered repo hex hash]
    <branch head hex node> <open/closed state> <branch name>
    <branch head hex node> <open/closed state> <branch name>
    ...

    The first line is used to check if the cache is still valid. If the
    branch cache is for a filtered repo view, an optional third hash is
    included that hashes the hashes of all filtered revisions.

    The open/closed state is represented by a single letter 'o' or 'c'.
    This field can be used to avoid changelog reads when determining if a
    branch head closes a branch or not.
    """

    def __init__(
        self,
        entries=(),
        tipnode=nullid,
        tiprev=nullrev,
        filteredhash=None,
        closednodes=None,
        hasnode=None,
    ):
        # type: (Union[Dict[bytes, List[bytes]], Iterable[Tuple[bytes, List[bytes]]]], bytes,  int, Optional[bytes], Optional[Set[bytes]], Optional[Callable[[bytes], bool]]) -> None
        """hasnode is a function which can be used to verify whether changelog
        has a given node or not. If it's not provided, we assume that every node
        we have exists in changelog"""
        self.tipnode = tipnode
        self.tiprev = tiprev
        self.filteredhash = filteredhash
        # closednodes is a set of nodes that close their branch. If the branch
        # cache has been updated, it may contain nodes that are no longer
        # heads.
        if closednodes is None:
            self._closednodes = set()
        else:
            self._closednodes = closednodes
        self._entries = dict(entries)
        # whether closed nodes are verified or not
        self._closedverified = False
        # branches for which nodes are verified
        self._verifiedbranches = set()
        self._hasnode = hasnode
        if self._hasnode is None:
            self._hasnode = lambda x: True

    def _verifyclosed(self):
        """ verify the closed nodes we have """
        if self._closedverified:
            return
        for node in self._closednodes:
            if not self._hasnode(node):
                _unknownnode(node)

        self._closedverified = True

    def _verifybranch(self, branch):
        """ verify head nodes for the given branch. """
        if branch not in self._entries or branch in self._verifiedbranches:
            return
        for n in self._entries[branch]:
            if not self._hasnode(n):
                _unknownnode(n)

        self._verifiedbranches.add(branch)

    def _verifyall(self):
        """ verifies nodes of all the branches """
        needverification = set(self._entries.keys()) - self._verifiedbranches
        for b in needverification:
            self._verifybranch(b)

    def __iter__(self):
        return iter(self._entries)

    def __setitem__(self, key, value):
        self._entries[key] = value

    def __getitem__(self, key):
        self._verifybranch(key)
        return self._entries[key]

    def __contains__(self, key):
        self._verifybranch(key)
        return key in self._entries

    def iteritems(self):
        for k, v in pycompat.iteritems(self._entries):
            self._verifybranch(k)
            yield k, v

    items = iteritems

    def hasbranch(self, label):
        """ checks whether a branch of this name exists or not """
        self._verifybranch(label)
        return label in self._entries

    @classmethod
    def fromfile(cls, repo):
        f = None
        try:
            f = repo.cachevfs(cls._filename(repo))
            lineiter = iter(f)
            cachekey = next(lineiter).rstrip(b'\n').split(b" ", 2)
            last, lrev = cachekey[:2]
            last, lrev = bin(last), int(lrev)
            filteredhash = None
            hasnode = repo.changelog.hasnode
            if len(cachekey) > 2:
                filteredhash = bin(cachekey[2])
            bcache = cls(
                tipnode=last,
                tiprev=lrev,
                filteredhash=filteredhash,
                hasnode=hasnode,
            )
            if not bcache.validfor(repo):
                # invalidate the cache
                raise ValueError('tip differs')
            bcache.load(repo, lineiter)
        except (IOError, OSError):
            return None

        except Exception as inst:
            if repo.ui.debugflag:
                msg = b'invalid %s: %s\n'
                repo.ui.debug(
                    msg
                    % (
                        _branchcachedesc(repo),
                        pycompat.bytestr(
                            inst
                        ),  # pytype: disable=wrong-arg-types
                    )
                )
            bcache = None

        finally:
            if f:
                f.close()

        return bcache

    def load(self, repo, lineiter):
        """fully loads the branchcache by reading from the file using the line
        iterator passed"""
        for line in lineiter:
            line = line.rstrip(b'\n')
            if not line:
                continue
            node, state, label = line.split(b" ", 2)
            if state not in b'oc':
                raise ValueError('invalid branch state')
            label = encoding.tolocal(label.strip())
            node = bin(node)
            self._entries.setdefault(label, []).append(node)
            if state == b'c':
                self._closednodes.add(node)

    @staticmethod
    def _filename(repo):
        """name of a branchcache file for a given repo or repoview"""
        filename = b"branch2"
        if repo.filtername:
            filename = b'%s-%s' % (filename, repo.filtername)
        return filename

    def validfor(self, repo):
        """Is the cache content valid regarding a repo

        - False when cached tipnode is unknown or if we detect a strip.
        - True when cache is up to date or a subset of current repo."""
        try:
            return (self.tipnode == repo.changelog.node(self.tiprev)) and (
                self.filteredhash == scmutil.filteredhash(repo, self.tiprev)
            )
        except IndexError:
            return False

    def _branchtip(self, heads):
        """Return tuple with last open head in heads and false,
        otherwise return last closed head and true."""
        tip = heads[-1]
        closed = True
        for h in reversed(heads):
            if h not in self._closednodes:
                tip = h
                closed = False
                break
        return tip, closed

    def branchtip(self, branch):
        """Return the tipmost open head on branch head, otherwise return the
        tipmost closed head on branch.
        Raise KeyError for unknown branch."""
        return self._branchtip(self[branch])[0]

    def iteropen(self, nodes):
        return (n for n in nodes if n not in self._closednodes)

    def branchheads(self, branch, closed=False):
        self._verifybranch(branch)
        heads = self._entries[branch]
        if not closed:
            heads = list(self.iteropen(heads))
        return heads

    def iterbranches(self):
        for bn, heads in pycompat.iteritems(self):
            yield (bn, heads) + self._branchtip(heads)

    def iterheads(self):
        """ returns all the heads """
        self._verifyall()
        return pycompat.itervalues(self._entries)

    def copy(self):
        """return an deep copy of the branchcache object"""
        return type(self)(
            self._entries,
            self.tipnode,
            self.tiprev,
            self.filteredhash,
            self._closednodes,
        )

    def write(self, repo):
        try:
            f = repo.cachevfs(self._filename(repo), b"w", atomictemp=True)
            cachekey = [hex(self.tipnode), b'%d' % self.tiprev]
            if self.filteredhash is not None:
                cachekey.append(hex(self.filteredhash))
            f.write(b" ".join(cachekey) + b'\n')
            nodecount = 0
            for label, nodes in sorted(pycompat.iteritems(self._entries)):
                label = encoding.fromlocal(label)
                for node in nodes:
                    nodecount += 1
                    if node in self._closednodes:
                        state = b'c'
                    else:
                        state = b'o'
                    f.write(b"%s %s %s\n" % (hex(node), state, label))
            f.close()
            repo.ui.log(
                b'branchcache',
                b'wrote %s with %d labels and %d nodes\n',
                _branchcachedesc(repo),
                len(self._entries),
                nodecount,
            )
        except (IOError, OSError, error.Abort) as inst:
            # Abort may be raised by read only opener, so log and continue
            repo.ui.debug(
                b"couldn't write branch cache: %s\n"
                % stringutil.forcebytestr(inst)
            )

    def update(self, repo, revgen):
        """Given a branchhead cache, self, that may have extra nodes or be
        missing heads, and a generator of nodes that are strictly a superset of
        heads missing, this function updates self to be correct.
        """
        starttime = util.timer()
        cl = repo.changelog
        # collect new branch entries
        newbranches = {}
        getbranchinfo = repo.revbranchcache().branchinfo
        for r in revgen:
            branch, closesbranch = getbranchinfo(r)
            newbranches.setdefault(branch, []).append(r)
            if closesbranch:
                self._closednodes.add(cl.node(r))

        # fetch current topological heads to speed up filtering
        topoheads = set(cl.headrevs())

        # new tip revision which we found after iterating items from new
        # branches
        ntiprev = self.tiprev

        # if older branchheads are reachable from new ones, they aren't
        # really branchheads. Note checking parents is insufficient:
        # 1 (branch a) -> 2 (branch b) -> 3 (branch a)
        for branch, newheadrevs in pycompat.iteritems(newbranches):
            bheads = self._entries.setdefault(branch, [])
            bheadset = {cl.rev(node) for node in bheads}

            # This have been tested True on all internal usage of this function.
            # run it again in case of doubt
            # assert not (set(bheadrevs) & set(newheadrevs))
            bheadset.update(newheadrevs)

            # This prunes out two kinds of heads - heads that are superseded by
            # a head in newheadrevs, and newheadrevs that are not heads because
            # an existing head is their descendant.
            uncertain = bheadset - topoheads
            if uncertain:
                floorrev = min(uncertain)
                ancestors = set(cl.ancestors(newheadrevs, floorrev))
                bheadset -= ancestors
            bheadrevs = sorted(bheadset)
            self[branch] = [cl.node(rev) for rev in bheadrevs]
            tiprev = bheadrevs[-1]
            if tiprev > ntiprev:
                ntiprev = tiprev

        if ntiprev > self.tiprev:
            self.tiprev = ntiprev
            self.tipnode = cl.node(ntiprev)

        if not self.validfor(repo):
            # cache key are not valid anymore
            self.tipnode = nullid
            self.tiprev = nullrev
            for heads in self.iterheads():
                tiprev = max(cl.rev(node) for node in heads)
                if tiprev > self.tiprev:
                    self.tipnode = cl.node(tiprev)
                    self.tiprev = tiprev
        self.filteredhash = scmutil.filteredhash(repo, self.tiprev)

        duration = util.timer() - starttime
        repo.ui.log(
            b'branchcache',
            b'updated %s in %.4f seconds\n',
            _branchcachedesc(repo),
            duration,
        )

        self.write(repo)


class remotebranchcache(branchcache):
    """Branchmap info for a remote connection, should not write locally"""

    def write(self, repo):
        pass


# Revision branch info cache

_rbcversion = b'-v1'
_rbcnames = b'rbc-names' + _rbcversion
_rbcrevs = b'rbc-revs' + _rbcversion
# [4 byte hash prefix][4 byte branch name number with sign bit indicating open]
_rbcrecfmt = b'>4sI'
_rbcrecsize = calcsize(_rbcrecfmt)
_rbcnodelen = 4
_rbcbranchidxmask = 0x7FFFFFFF
_rbccloseflag = 0x80000000


class revbranchcache(object):
    """Persistent cache, mapping from revision number to branch name and close.
    This is a low level cache, independent of filtering.

    Branch names are stored in rbc-names in internal encoding separated by 0.
    rbc-names is append-only, and each branch name is only stored once and will
    thus have a unique index.

    The branch info for each revision is stored in rbc-revs as constant size
    records. The whole file is read into memory, but it is only 'parsed' on
    demand. The file is usually append-only but will be truncated if repo
    modification is detected.
    The record for each revision contains the first 4 bytes of the
    corresponding node hash, and the record is only used if it still matches.
    Even a completely trashed rbc-revs fill thus still give the right result
    while converging towards full recovery ... assuming no incorrectly matching
    node hashes.
    The record also contains 4 bytes where 31 bits contains the index of the
    branch and the last bit indicate that it is a branch close commit.
    The usage pattern for rbc-revs is thus somewhat similar to 00changelog.i
    and will grow with it but be 1/8th of its size.
    """

    def __init__(self, repo, readonly=True):
        assert repo.filtername is None
        self._repo = repo
        self._names = []  # branch names in local encoding with static index
        self._rbcrevs = bytearray()
        self._rbcsnameslen = 0  # length of names read at _rbcsnameslen
        try:
            bndata = repo.cachevfs.read(_rbcnames)
            self._rbcsnameslen = len(bndata)  # for verification before writing
            if bndata:
                self._names = [
                    encoding.tolocal(bn) for bn in bndata.split(b'\0')
                ]
        except (IOError, OSError):
            if readonly:
                # don't try to use cache - fall back to the slow path
                self.branchinfo = self._branchinfo

        if self._names:
            try:
                data = repo.cachevfs.read(_rbcrevs)
                self._rbcrevs[:] = data
            except (IOError, OSError) as inst:
                repo.ui.debug(
                    b"couldn't read revision branch cache: %s\n"
                    % stringutil.forcebytestr(inst)
                )
        # remember number of good records on disk
        self._rbcrevslen = min(
            len(self._rbcrevs) // _rbcrecsize, len(repo.changelog)
        )
        if self._rbcrevslen == 0:
            self._names = []
        self._rbcnamescount = len(self._names)  # number of names read at
        # _rbcsnameslen

    def _clear(self):
        self._rbcsnameslen = 0
        del self._names[:]
        self._rbcnamescount = 0
        self._rbcrevslen = len(self._repo.changelog)
        self._rbcrevs = bytearray(self._rbcrevslen * _rbcrecsize)
        util.clearcachedproperty(self, b'_namesreverse')

    @util.propertycache
    def _namesreverse(self):
        return {b: r for r, b in enumerate(self._names)}

    def branchinfo(self, rev):
        """Return branch name and close flag for rev, using and updating
        persistent cache."""
        changelog = self._repo.changelog
        rbcrevidx = rev * _rbcrecsize

        # avoid negative index, changelog.read(nullrev) is fast without cache
        if rev == nullrev:
            return changelog.branchinfo(rev)

        # if requested rev isn't allocated, grow and cache the rev info
        if len(self._rbcrevs) < rbcrevidx + _rbcrecsize:
            return self._branchinfo(rev)

        # fast path: extract data from cache, use it if node is matching
        reponode = changelog.node(rev)[:_rbcnodelen]
        cachenode, branchidx = unpack_from(
            _rbcrecfmt, util.buffer(self._rbcrevs), rbcrevidx
        )
        close = bool(branchidx & _rbccloseflag)
        if close:
            branchidx &= _rbcbranchidxmask
        if cachenode == b'\0\0\0\0':
            pass
        elif cachenode == reponode:
            try:
                return self._names[branchidx], close
            except IndexError:
                # recover from invalid reference to unknown branch
                self._repo.ui.debug(
                    b"referenced branch names not found"
                    b" - rebuilding revision branch cache from scratch\n"
                )
                self._clear()
        else:
            # rev/node map has changed, invalidate the cache from here up
            self._repo.ui.debug(
                b"history modification detected - truncating "
                b"revision branch cache to revision %d\n" % rev
            )
            truncate = rbcrevidx + _rbcrecsize
            del self._rbcrevs[truncate:]
            self._rbcrevslen = min(self._rbcrevslen, truncate)

        # fall back to slow path and make sure it will be written to disk
        return self._branchinfo(rev)

    def _branchinfo(self, rev):
        """Retrieve branch info from changelog and update _rbcrevs"""
        changelog = self._repo.changelog
        b, close = changelog.branchinfo(rev)
        if b in self._namesreverse:
            branchidx = self._namesreverse[b]
        else:
            branchidx = len(self._names)
            self._names.append(b)
            self._namesreverse[b] = branchidx
        reponode = changelog.node(rev)
        if close:
            branchidx |= _rbccloseflag
        self._setcachedata(rev, reponode, branchidx)
        return b, close

    def setdata(self, branch, rev, node, close):
        """add new data information to the cache"""
        if branch in self._namesreverse:
            branchidx = self._namesreverse[branch]
        else:
            branchidx = len(self._names)
            self._names.append(branch)
            self._namesreverse[branch] = branchidx
        if close:
            branchidx |= _rbccloseflag
        self._setcachedata(rev, node, branchidx)
        # If no cache data were readable (non exists, bad permission, etc)
        # the cache was bypassing itself by setting:
        #
        #   self.branchinfo = self._branchinfo
        #
        # Since we now have data in the cache, we need to drop this bypassing.
        if 'branchinfo' in vars(self):
            del self.branchinfo

    def _setcachedata(self, rev, node, branchidx):
        """Writes the node's branch data to the in-memory cache data."""
        if rev == nullrev:
            return
        rbcrevidx = rev * _rbcrecsize
        if len(self._rbcrevs) < rbcrevidx + _rbcrecsize:
            self._rbcrevs.extend(
                b'\0'
                * (len(self._repo.changelog) * _rbcrecsize - len(self._rbcrevs))
            )
        pack_into(_rbcrecfmt, self._rbcrevs, rbcrevidx, node, branchidx)
        self._rbcrevslen = min(self._rbcrevslen, rev)

        tr = self._repo.currenttransaction()
        if tr:
            tr.addfinalize(b'write-revbranchcache', self.write)

    def write(self, tr=None):
        """Save branch cache if it is dirty."""
        repo = self._repo
        wlock = None
        step = b''
        try:
            # write the new names
            if self._rbcnamescount < len(self._names):
                wlock = repo.wlock(wait=False)
                step = b' names'
                self._writenames(repo)

            # write the new revs
            start = self._rbcrevslen * _rbcrecsize
            if start != len(self._rbcrevs):
                step = b''
                if wlock is None:
                    wlock = repo.wlock(wait=False)
                self._writerevs(repo, start)

        except (IOError, OSError, error.Abort, error.LockError) as inst:
            repo.ui.debug(
                b"couldn't write revision branch cache%s: %s\n"
                % (step, stringutil.forcebytestr(inst))
            )
        finally:
            if wlock is not None:
                wlock.release()

    def _writenames(self, repo):
        """ write the new branch names to revbranchcache """
        if self._rbcnamescount != 0:
            f = repo.cachevfs.open(_rbcnames, b'ab')
            if f.tell() == self._rbcsnameslen:
                f.write(b'\0')
            else:
                f.close()
                repo.ui.debug(b"%s changed - rewriting it\n" % _rbcnames)
                self._rbcnamescount = 0
                self._rbcrevslen = 0
        if self._rbcnamescount == 0:
            # before rewriting names, make sure references are removed
            repo.cachevfs.unlinkpath(_rbcrevs, ignoremissing=True)
            f = repo.cachevfs.open(_rbcnames, b'wb')
        f.write(
            b'\0'.join(
                encoding.fromlocal(b)
                for b in self._names[self._rbcnamescount :]
            )
        )
        self._rbcsnameslen = f.tell()
        f.close()
        self._rbcnamescount = len(self._names)

    def _writerevs(self, repo, start):
        """ write the new revs to revbranchcache """
        revs = min(len(repo.changelog), len(self._rbcrevs) // _rbcrecsize)
        with repo.cachevfs.open(_rbcrevs, b'ab') as f:
            if f.tell() != start:
                repo.ui.debug(
                    b"truncating cache/%s to %d\n" % (_rbcrevs, start)
                )
                f.seek(start)
                if f.tell() != start:
                    start = 0
                    f.seek(start)
                f.truncate()
            end = revs * _rbcrecsize
            f.write(self._rbcrevs[start:end])
        self._rbcrevslen = revs