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1 Mercurial can be augmented with Rust extensions for speeding up certain |
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2 operations. |
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3 |
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4 Compatibility |
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5 ============= |
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6 |
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7 Though the Rust extensions are only tested by the project under Linux, users of |
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8 MacOS, FreeBSD and other UNIX-likes have been using the Rust extensions. Your |
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9 mileage may vary, but by all means do give us feedback or signal your interest |
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10 for better support. |
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11 |
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12 No Rust extensions are available for Windows at this time. |
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13 |
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14 Features |
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15 ======== |
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16 |
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17 The following operations are sped up when using Rust: |
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18 - discovery of differences between repositories (pull/push) |
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19 - nodemap (see :hg:`help config.format.use-persistent-nodemap`) |
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20 - all commands using the dirstate (status, commit, diff, add, update, etc.) |
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21 - dirstate-v2 (see :hg:`help config.format.exp-rc-dirstate-v2`) |
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22 - iteration over ancestors in a graph |
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23 |
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24 More features are in the works, and improvements on the above listed are still |
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25 in progress. For more experimental work see the "rhg" section. |
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26 |
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27 Checking for Rust |
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28 ================= |
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29 |
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30 You may already have the Rust extensions depending on how you install Mercurial. |
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31 |
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32 $ hg debuginstall | grep -i rust |
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33 checking Rust extensions (installed) |
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34 checking module policy (rust+c-allow) |
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35 |
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36 If those lines don't even exist, you're using an old version of `hg` which does |
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37 not have any Rust extensions yet. |
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38 |
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39 Installing |
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40 ========== |
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41 |
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42 You will need `cargo` to be in your `$PATH`. See the "MSRV" section for which |
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43 version to use. |
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44 |
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45 Using pip |
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46 --------- |
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47 |
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48 Users of `pip` can install the Rust extensions with the following command: |
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49 |
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50 $ pip install mercurial --global-option --rust --no-use-pep517 |
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51 |
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52 `--no-use-pep517` is here to tell `pip` to preserve backwards compatibility with |
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53 the legacy `setup.py` system. Mercurial has not yet migrated its complex setup |
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54 to the new system, so we still need this to add compiled extensions. |
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55 |
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56 This might take a couple of minutes because you're compiling everything. |
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57 |
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58 See the "Checking for Rust" section to see if the install succeeded. |
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59 |
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60 From your distribution |
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61 ---------------------- |
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62 |
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63 Some distributions are shipping Mercurial with Rust extensions enabled and |
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64 pre-compiled (meaning you won't have to install `cargo`), or allow you to |
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65 specify an install flag. Check with your specific distribution for how to do |
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66 that, or ask their team to add support for hg+Rust! |
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67 |
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68 From source |
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69 ----------- |
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70 |
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71 Please refer to the `rust/README.rst` file in the Mercurial repository for |
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72 instructions on how to install from source. |
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73 |
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74 MSRV |
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75 ==== |
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76 |
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77 The minimum supported Rust version is currently 1.48.0. The project's policy is |
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78 to follow the version from Debian stable, to make the distributions' job easier. |
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79 |
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80 rhg |
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81 === |
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82 |
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83 There exists an experimental pure-Rust version of Mercurial called `rhg` with a |
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84 fallback mechanism for unsupported invocations. It allows for much faster |
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85 execution of certain commands while adding no discernable overhead for the rest. |
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86 |
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87 The only way of trying it out is by building it from source. Please refer to |
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88 `rust/README.rst` in the Mercurial repository. |
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89 |
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90 Contributing |
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91 ============ |
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92 |
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93 If you would like to help the Rust endeavor, please refer to `rust/README.rst` |
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94 in the Mercurial repository. |