Mercurial > evolve
view docs/obs-terms.rst @ 1567:536fdfa3c48b
evolve: extract logic to new method _relocatecommit
This patch introduces a new method _relocatecommit to commit current state
after merge states in relocate method.
This simplifies the code of the method relocate and allows us to modify it later to
support a continued keywork to implement evolve state.
| author | Shusen LIU <liushusen@fb.com> |
|---|---|
| date | Mon, 14 Dec 2015 17:02:55 -0800 |
| parents | 6f2c1574eda8 |
| children | 49d4f4bfd2ab |
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.. Copyright 2011 Pierre-Yves David <pierre-yves.david@ens-lyon.org> .. Logilab SA <contact@logilab.fr> ----------------------------------- Terminology of the obsolete concept ----------------------------------- Obsolete markers ---------------- The mutable concept is based on **obsolete markers**. Creating an obsolete marker registers a relation between an old obsoleted changeset and its newer version. Old changesets are called **precursors** while their new versions are called **successors**. A marker always registers a single *precursor* and: - no *successor*: the *precursor* is just discarded. - one *successor*: the *precursor* has been rewritten - multiple *successors*: the *precursor* were splits in multiple changesets. .. The *precursors* and *successors* terms can be used on changeset directy: .. :precursors: of a changeset `A` are changesets used as *precursors* by .. obsolete marker using changeset `A` as *successors* .. :successors: of a changeset `B` are changesets used as *successors* by .. obsolete marker using changeset `B` as *precursors* Chaining obsolete markers is allowed to rewrite a changeset that is already a *successor*. This is a kind of *second order version control*. To clarify ambiguous situations one can use **direct precursors** or **direct successors** to name changesets that are directly related. The set of all *obsolete markers* forms a direct acyclic graph the same way standard *parents*/*children* relation does. In this graph we have: :any precursors: are transitive precursors of a changeset: *direct precursors* and *precursors* of *precursors*. :any successors: are transitive successors of a changeset: *direct successors* and *successors* of *successors*) Obsolete markers may refer changesets that are not known locally. So, *direct precursors* of a changeset may be unknown locally. This is why we usually focus on the **first known precursors** of the rewritten changeset. The same apply for *successors*. Changeset in *any successors* which are not **obsolete** are called **newest successors**.. .. note:: I'm not very happy with this naming scheme and I'm looking for a better distinction between *direct successors* and **any successors**. Possible changesets "type" -------------------------- The following table describes names and behaviors of changesets affected by obsolete markers. The left column describes generic categories and the right columns are about sub-categories. +---------------------+--------------------------+-----------------------------+ | **mutable** | **obsolete** | **extinct** | | | | | | Changeset in either | Obsolete changeset is | *extinct* changeset is | | *draft* or *secret* | *mutable* used as a | *obsolete* which has only | | phase. | *precursor*. | *obsolete* descendants. | | | | | | | A changeset is used as | They can safely be: | | | a *precursor* when at | | | | least one obsolete | - hidden in the UI, | | | marker refers to it | - silently excluded from | | | as precursors. | pull and push operations | | | | - mostly ignored | | | | - garbage collected | | | | | | | +-----------------------------+ | | | | | | | **suspended** | | | | | | | | *suspended* changeset is | | | | *obsolete* with at least | | | | one non-obsolete descendant | | | | | | | | Thoses descendants prevent | | | | properties of extincts | | | | changesets to apply. But | | | | they will refuse to be | | | | pushed without --force. | | | | | | +--------------------------+-----------------------------+ | | | | | | **troubled** | **unstable** | | | | | | | *troubled* has | *unstable* is a changeset | | | unresolved issue caused | with obsolete ancestors. | | | by *obsolete* relations. | | | | | | | | Possible issues are | It must be rebased on a | | | listed in the next | non *troubled* base to | | | column. It is possible | solve the problem. | | | for *troubled* | | | | changeset to combine | (possible alternative name: | | | multiple issue at once. | precarious) | | | (a.k.a. divergent and | | | | unstable) +-----------------------------+ | | | | | | (possible alternative | **bumped** | | | names: unsettled, | | | | troublesome | *bumped* is a changeset | | | | that tries to be successor | | | | of public changesets. | | | | | | | | Public changeset can't | | | | be deleted and replace | | | | *bumped* | | | | need to be converted into | | | | an overlay to this public | | | | changeset. | | | | | | | | (possible alternative names:| | | | mislead, naive, unaware, | | | | mindless, disenchanting) | | | | | | | +-----------------------------+ | | | **divergent** | | | | | | | | *divergent* is changeset | | | | that appears when multiple | | | | changesets are successors | | | | of the same precursor. | | | | | | | | *divergent* are solved | | | | through a three ways merge | | | | between the two | | | | *divergent* , | | | | using the last "obsolete- | | | | -common-ancestor" as the | | | | base. | | | | | | | | (*splitting* is | | | | properly not detected as a | | | | conflict) | | | | | | | | (possible alternative names:| | | | clashing, rival, concurent, | | | | conflicting) | | | | | | +--------------------------+-----------------------------+ | | | | | Mutable changesets which are neither *obsolete* or | | | *troubled* are *"ok"*. | | | | | | Do we really need a name for it ? *"ok"* is a pretty | | | crappy name :-/ other possibilities are: | | | | | | - stable (confusing with stable branch) | | | - sane | | | - healthy | | | | +---------------------+--------------------------------------------------------+ | | | **immutable** | | | | Changesets in the *public* phases. | | | | Rewriting operation refuse to work on immutable changeset. | | | | Obsolete markers that refer an immutable changeset as precursors have | | no effect on the precussors but may have effect on the successors. | | | | When a *mutable* changeset becomes *immutable* (changing its phase from draft| | to public) it is just *immutable* and loose any property of it's former | | state. | | | | The phase properties says that public changesets stay as *immutable* forever.| | | +------------------------------------------------------------------------------+ Command and operation name -------------------------- Existing terms `````````````` Mercurial core already uses the following terms: :amend: to rewrite a changeset :graft: to copy a changeset :rebase: to move a changeset Uncommit ```````` Remove files from a commit (and leave them as dirty in the working directory) The *evolve* extension have an `uncommit` command that aims to replace most `rollback` usage. Fold ```` Collapse multiple changesets into a unique one. The *evolve* extension will have a `fold` command. Prune ````` Make a changeset obsolete without successors. This an important operation as it should mostly replace *strip*. Alternative names: - kill: shall has funny effects when you forget "hg" in front of ``hg kill``. - obsolete: too vague, too long and too generic. evolve `````` Automatically resolve *troublesome* changesets (*unstable*, *bumped* and *divergent*) This is an important name as hg pull/push will suggest it the same way it suggest merging when you add heads. alternative names: - solve (too generic ?) - stabilize