push: rework the computation of fallbackheads to be correct
The previous computation tried to be smart but ended up being wrong. This was
caught by phase movement test while reworking the phase discovery logic to be
faster.
The previous logic was failing to catch case where the pushed set was not based
on a common heads (i.e. when the discovery seemed to have "over discovered"
content, outside the pushed set)
In the following graph, `e` is a common head and we `hg push -r f`. We need to
detect `c` as a fallback heads and we previous failed to do so::
e
|
d f
|/
c
|
b
|
a
The performance impact of the change seems minimal. On the most impacted
repository at hand (mozilla-try), the slowdown seems mostly mixed in the
overall noise `hg push` but seems to be in the hundred of milliseconds order of
magnitude. When using rust, we seems to be a bit faster, probably because we
leverage more accelaratd internals.
I added a couple of performance related common for further investigation later
on.
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!-- Created with Inkscape (http://www.inkscape.org/) -->
<svg id="Layer_1" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns="http://www.w3.org/2000/svg" xml:space="preserve" height="120" width="100" version="1.0" xmlns:cc="http://web.resource.org/cc/" xmlns:dc="http://purl.org/dc/elements/1.1/" viewBox="0 0 124.766 152.099"><metadata id="metadata6845"><rdf:RDF><cc:Work rdf:about=""><dc:format>image/svg+xml</dc:format><dc:type rdf:resource="http://purl.org/dc/dcmitype/StillImage"/><dc:title>Mercurial "droplets" logo</dc:title><dc:creator><cc:Agent><dc:title>Cali Mastny and Olivia Mackall</dc:title></cc:Agent></dc:creator><cc:license rdf:resource="http://creativecommons.org/licenses/GPL/2.0/"/><dc:date>Feb 12 2008</dc:date></cc:Work><cc:License rdf:about="http://creativecommons.org/licenses/GPL/2.0/"><cc:permits rdf:resource="http://web.resource.org/cc/Reproduction"/><cc:permits rdf:resource="http://web.resource.org/cc/Distribution"/><cc:requires rdf:resource="http://web.resource.org/cc/Notice"/><cc:permits rdf:resource="http://web.resource.org/cc/DerivativeWorks"/><cc:requires rdf:resource="http://web.resource.org/cc/ShareAlike"/><cc:requires rdf:resource="http://web.resource.org/cc/SourceCode"/></cc:License></rdf:RDF></metadata>
<rect id="rect6847" stroke-linejoin="miter" style="stroke-dasharray:none;" height="150.12" width="124.77" stroke="#000" stroke-miterlimit="4" y="0.98776" x="0.3169" stroke-width="1.9755" fill="#FFF"/><path id="text2611" style="stroke-dasharray:none;" d="M9.848,124.61c1.777-0.79,3.665-1.18,5.479-1.18,1.74,0,2.851,0.43,3.48,1.32,1.332-0.89,3.146-1.32,4.553-1.32,4.221,0,4.369,1.71,4.369,6.73v11.11c0,0.49,0.074,0.49-2.036,0.49v-11.81c0-3.63-0.074-4.74-2.48-4.74-1.073,0-2.184,0.25-3.369,1.03v15.27c-0.037,0.15-0.111,0.18-0.369,0.22-0.038,0-0.074,0.03-0.112,0.03h-1.555v-11.81c0-3.49,0-4.77-2.517-4.77-1.074,0-2.147,0.21-3.406,0.82v15.27c0,0.49,0.074,0.49-2.0361,0.49v-17.15m27.831-1.18c-3.146,0-6.626,0.89-6.626,10.4,0,7.33,2.554,8.47,6.071,8.47,2.701,0,5.034-0.89,5.034-1.32,0-0.53-0.074-1.35-0.259-1.82-1.148,0.79-2.777,1.21-4.59,1.21-2.48,0-4.146-0.71-4.184-6.22,1.629,0,5.776-0.04,8.848-0.65,0.259-1.17,0.37-2.88,0.37-4.37,0-3.56-1.444-5.7-4.664-5.7m-0.185,1.78c2.221,0,2.813,1.46,2.85,4.31,0,0.75-0.037,1.64-0.148,2.49-2.073,0.5-5.591,0.5-7.072,0.5,0.261-6.48,2.481-7.3,4.37-7.3m8.07-0.21c1.739-1.14,3.332-1.57,4.961-1.57,1.814,0,2.666,0.5,2.666,1.11,0,0.35-0.112,0.96-0.297,1.31-0.519-0.28-1.11-0.53-2.074-0.53-1.184,0-2.295,0.32-3.183,1.1v14.85c0,0.49,0.037,0.49-2.073,0.49v-16.76m18.69-0.39c0-0.47-1.554-1.18-3.11-1.18-2.999,0-6.664,1.03-6.664,9.83,0,8.33,2.222,9.07,6.109,9.07,1.924,0,3.665-1.03,3.665-1.6,0-0.32-0.074-0.82-0.26-1.24-0.778,0.56-1.962,1.1-3.22,1.1-2.665,0-4.22-0.75-4.22-7.23,0-7.15,2.554-8.15,4.775-8.15,1.258,0,1.962,0.36,2.665,0.82,0.186-0.43,0.26-1.03,0.26-1.42m14.181,16.55c-1.63,0.82-3.776,1.14-5.627,1.14-4.739,0-5.442-1.99-5.442-6.73v-11.14c0-0.46-0.037-0.46,2.074-0.46v11.82c0,3.56,0.517,4.77,3.294,4.77,1.073,0,2.554-0.22,3.665-0.86v-15.27c0-0.46-0.074-0.46,2.036-0.46v17.19m4.221-16.16c1.739-1.14,3.332-1.57,4.96-1.57,1.814,0,2.666,0.5,2.666,1.11,0,0.35-0.111,0.96-0.296,1.31-0.519-0.28-1.111-0.53-2.074-0.53-1.184,0-2.295,0.32-3.183,1.1v14.85c0,0.49,0.037,0.49-2.073,0.49v-16.76m12.379-1.03c-1.629,0-2.11,0-2.11,0.96v16.83c2.073,0,2.11,0,2.11-0.49v-17.3m-2.184-6.27c0,1.18,0.37,1.6,1.11,1.64,0.851,0,1.259-0.61,1.259-1.67,0.037-1.11-0.26-1.61-1.111-1.61-0.814,0-1.221,0.61-1.258,1.64m5.696,7.3c0-0.39,0.074-0.61,0.222-0.71,0.704-0.39,3.41-0.86,6.48-0.86,2.33,0,3.81,1.11,3.81,4.31v2.31c0,6.34-0.18,11.07-0.18,11.07-0.85,0.47-2.45,1.18-5.04,1.18-2.66,0.03-5.329-0.22-5.329-5.48,0-5.02,2.739-5.81,5.479-5.81,1.04,0,2.26,0.11,3.07,0.43v-3.31c0-2.31-1.18-2.81-2.59-2.81-1.89,0-4.514,0.35-5.662,0.89-0.222-0.39-0.26-1-0.26-1.21m8.512,7.9c-0.7-0.25-1.7-0.35-2.4-0.35-2.11,0-4.04,0.42-4.04,4.34,0,3.66,1.59,3.7,3.48,3.7,1.19,0,2.37-0.32,2.78-0.75,0,0,0.18-4.27,0.18-6.94m7.86,8.37c0,0.49,0.04,0.49-2.04,0.49v-25.2c0-0.96,0.41-0.96,2.04-0.96v25.67" stroke-miterlimit="4" stroke-width="2.02999997" fill="#010101"/><g id="g4503" transform="matrix(0.9351326,0,0,0.9351326,150.39508,-1.251766)"><path id="path2339" fill="#1b1a1b" d="M-45.75,92.692c20.04-33.321-4.232-87.363-48.614-81.873-40.096,4.958-40.746,47.165-5.405,57.191,30.583,8.685,6.318,28.084,7.027,41,0.712,12.92,26.587,17.6,46.992-16.318z"/><circle id="circle2341" transform="matrix(1.0917947,-0.2858168,0.2858168,1.0917947,-180.30817,13.494135)" cy="85.364" cx="33.728" r="15.414" fill="#1b1a1b"/><path id="path2343" fill="#1b1a1b" d="M-140.06,48.936c-6.26,0.606-10.84,6.164-10.24,12.422,0.61,6.262,6.17,10.847,12.43,10.241,6.26-0.614,10.84-6.171,10.23-12.43-0.61-6.253-6.16-10.839-12.42-10.233z"/><path id="path2561" fill="#bfbfbf" d="M-44.993,91.34c20.041-33.321-4.231-87.363-48.613-81.873-40.104,4.9568-40.744,47.166-5.406,57.193,30.583,8.684,6.318,28.083,7.027,41,0.713,12.92,26.587,17.6,46.992-16.32z"/><path id="path2563" fill="#000" d="M-86.842,112.76c-1.215-1.97,0.642-4.16,2.551-3.99,3.039,0.26,9.655-0.04,14.876-3,13.043-7.39,33.114-42.966,23.019-65.405-4.519-10.044-6.72-12.92-11.374-17.833-0.95-1.002-0.405-0.948,0.238-0.609,2.517,1.321,6.94,6.437,11.477,14.765,7.664,14.069,7.267,30.795,4.416,41.287-1.986,7.299-8.825,23.815-18.842,30.955-10.039,7.15-21.785,11.26-26.361,3.83z"/><path id="path2565" fill="#000" d="M-95.93,66.591c-6.83-2.028-15.64-4.853-20.74-11.517-3.75-4.914-5.66-10.277-6.15-13.318-0.17-1.085-0.32-1.991-0.01-2.24,0.15-0.117,2.81,5.896,6.79,10.936,3.97,5.04,9.53,7.988,14.16,9.059,4.117,0.952,12.646,3.044,15.532,5.503,2.967,2.527,3.215,7.987,2.216,8.603-1.006,0.62-3.048-4.429-11.798-7.026z"/><path id="path2567" fill="#FFF" d="M-81.841,113.72c-0.132,1.57,1.665,1.87,4.083,1.51,3.099-0.46,5.72-0.81,9.287-2.6,4.835-2.42,9.728-5.89,13.312-10.57,10.692-13.945,14.478-30.45,13.895-32.824-0.195,1.961-2.776,12.253-8.679,21.532-7.582,11.922-13.079,18.262-25.758,21.342-3.529,0.86-5.967-0.45-6.14,1.61z"/><path id="path2569" fill="#FFF" d="M-109.96,59.479c1.44,1.225,4.4,2.857,10.223,4.767,7.031,2.305,10.455,4.304,11.888,5.262,1.52,1.018,2.483,3.288,2.578,1.272,0.099-2.019-1.145-3.755-3.921-4.675-1.878-0.624-5.038-2.109-8.067-2.707-1.946-0.384-5.111-1.146-7.831-1.978-1.48-0.457-3-1.258-4.87-1.941z"/><circle id="circle2577" transform="matrix(1.0917947,-0.2858168,0.2858168,1.0917947,-180.30817,13.494135)" cy="84.375" cx="34.681" r="15.414" fill="#bfbfbf"/><path id="path2579" fill="#000" d="M-128.68,108.38c13.53,12.54,33.894-4.69,24.93-19.897-1.01-1.708-2.32-3.009-1.89-1.7,2.87,8.747,0.22,15.667-4.72,19.227-4.85,3.5-11.51,4.09-16.84,1.32-1.57-0.81-2.22,0.37-1.48,1.05z"/><path id="path2585" fill="#FFF" d="M-118.07,110.95c1.73-0.36,11.75-2.95,14.1-11.194,0.73-2.569,0.86-2.053,0.66-0.661-1.06,7.105-7.78,12.345-13.49,12.545-1.16,0.12-2.68-0.39-1.27-0.69z"/><path id="path2589" fill="#bfbfbf" d="M-139.3,47.584c-6.26,0.605-10.84,6.164-10.24,12.422,0.61,6.261,6.17,10.847,12.43,10.241,6.25-0.614,10.84-6.173,10.23-12.431-0.61-6.254-6.17-10.838-12.42-10.232z"/><path id="path2591" fill="#000" d="M-144.47,67.571c0.07,0.805,1.17,1.838,2.9,2.312,1.49,0.408,5.32,1.45,10.25-1.658,4.92-3.108,5.49-11.421,3.25-13.865-0.69-1.239-1.59-2.14-0.88-0.164,1.81,4.99-1.7,9.659-4.74,11.82-3.03,2.162-6.88,1.139-8.45,0.66s-2.4,0.064-2.33,0.895z"/><path id="path2597" fill="#FFF" d="M-138.11,68.688c0.45-0.406,2.73-0.24,4.79-1.35,2.07-1.109,4.52-3.54,4.95-6.994,0.26-2.029,0.34-1.519,0.44-0.415-0.32,5.743-5.6,8.916-8.62,9.334-0.82,0.113-2.25,0.044-1.56-0.575z"/><path id="path2561_1_" fill="#999" d="M-47.767,69.694c8.532-24.594-9.323-61.736-45.446-57.268-32.637,4.035-33.167,38.389-4.4,46.55,32.582,4.933,12.962,29.512,10.179,41.904-2.495,11.11,26.331,12.94,39.667-31.186z"/><path id="path2571" fill="#f3f3f3" d="M-70.093,88.904c-8.827-1.092-21.529,18.836-9.552,16.506,5.756-0.86,10.525-2.89,14.794-7.762,5.567-6.353,13.883-20.074,16.288-28.94,2.025-7.476,1.007-19.057-1.081-8.175-2.142,11.167-11.623,29.464-20.449,28.371z"/><path id="path2581" fill="#999" d="M-129.39,104.85c2.05,0.03,3.28,0.32,5.35,1.77,4.09,1.7,11.61,0.62,15.09-3.95,3.47-4.57,3.58-10.868,2.26-14.674-3.24-9.314-16.99-9.149-23.13-1.417-6.64,8.636-1.61,18.231,0.43,18.271z"/><path id="path2593_2_" fill="#999" d="M-147.64,61.684c0.41,1.282,1.45,3.154,3.65,3.466,2.94,0.417,3.54,1.743,7,1.055,3.47-0.688,6.09-3.528,7.14-6.67,1.21-4.347-0.59-6.591-3.31-8.595-2.71-2.003-8.67-1.788-12.23,1.458-2.53,2.305-3.24,6.163-2.25,9.286z"/><path id="path256" fill="#f3f3f3" d="M-136.11,64.558c2.66-0.697,6.18-4.325,4.44-7.096-2.16-3.413-8.17-0.491-8.37,3.309-0.21,3.802,1.11,4.526,3.93,3.787z"/><path id="path258" fill="#f3f3f3" d="M-116.12,105.51c2.28-0.6,9.24-3.43,7.93-13.547-0.66-5.126-3.46,6.361-8.63,8.077-7.85,2.61-6.97,7.48,0.7,5.47z"/></g>
</svg>
