src/ledger/upgrade.bend
ezx@1.5.0.0 · 219 lines · 0 definitions
1# ledger/upgrade: what `ez lock --upgrade` may do to one dependency, before
2# it talks to a remote. The ledger pins exact commits. A tag is the only
3# floating name a person wrote down, so that is what gets re-resolved. A pin
4# with no tag fast-forwards to the default branch tip when the commit is an
5# ancestor of it, and stays a commit pin. A hub package is the hash itself.
6# `vend` says the tree under `.ez/lib/<hash>` is committed, so a move lays the
7# new tree there; the allowlist that names it is `ledger/ignore.bend`'s,
8# derived from the ledger the move writes. A move also rewrites an
9# `import 0x<hash>/` line that names the old hash.
10import Base
11import ezx@1.5.0.0/src/ledger/manifest.bend as M
12
13# what an upgrade will ask the remote, once the ledger has been read
14type Aim is Data:
15 Hold{}
16 Follow{+ref: String}
17 Forward{}
18
19# what that answer means for the pin
20type Verdict is Data:
21 Keep{}
22 Drift{}
23 Off{}
24 Advance{rev: String, tag: String}
25
26# one hash that moved, and the hash that replaces it: an import line to
27# rewrite, or a committed tree to remove
28type Swap is Data:
29 Swap{old: String, new: String}
30
31# an empty `--package` is every dependency; a name is that one
32def chosen.go(all: Bool, +only: String, +name: String) -> Bool:
33 match all:
34 case True{}:
35 True{}
36 case False{}:
37 String.eq(only, name)
38
39# an empty `--package` is every dependency; a name is that one
40def chosen(+only: String, +name: String) -> Bool:
41 chosen.go(String.is_empty(only), only, name)
42
43# the rest of the scan only when this one was not it
44def known.step(hit: Bool, rest: Unit -> Bool) -> Bool:
45 match hit:
46 case True{}:
47 True{}
48 case False{}:
49 rest(Unit{})
50
51# whether the ledger names this dependency
52def known.in(ds: List<&2, M.Dep>, +name: String) -> Bool:
53 match ds:
54 case []:
55 False{}
56 case +h <> t:
57 known.step(String.eq(M.dep.name(h), name), _u => known.in(t, name))
58
59# `--package` with no such dependency is a mistake, and no filter is not
60def known.go(all: Bool, ds: List<&2, M.Dep>, +name: String) -> Bool:
61 match all:
62 case True{}:
63 True{}
64 case False{}:
65 known.in(ds, name)
66
67# whether the ledger names the dependency `--package` asked for
68def known(+only: String, ds: List<&2, M.Dep>) -> Bool:
69 known.go(String.is_empty(only), ds, only)
70
71# a selected git pin with no tag follows the default branch
72def aim.tag(bare: Bool, +tag: String) -> Aim:
73 match bare:
74 case True{}:
75 Forward{}
76 case False{}:
77 Follow{tag}
78
79# a selected hub pin has nothing to follow
80def aim.src(source: M.Source) -> Aim:
81 match source:
82 case M.Hub{_named}:
83 Hold{}
84 case M.Git{_url, _rev, +tag, _root, _nar, _vend}:
85 aim.tag(String.is_empty(tag), tag)
86
87# what this dependency is asked. Unselected dependencies are left alone,
88# including a git one, so `--package` does not move its neighbours.
89def aim(sel: Bool, source: M.Source) -> Aim:
90 match sel:
91 case False{}:
92 Hold{}
93 case True{}:
94 aim.src(source)
95
96# the same commit either still hashes to the pin or it does not
97def judge.same(agree: Bool) -> Verdict:
98 match agree:
99 case True{}:
100 Keep{}
101 case False{}:
102 Drift{}
103
104# a different commit is the upgrade only when it descends from the pin
105def judge.move(onward: Bool, +rev: String, +tag: String) -> Verdict:
106 match onward:
107 case True{}:
108 Advance{rev, tag}
109 case False{}:
110 Off{}
111
112# `same` is the resolved commit against the pin. `onward` is that commit
113# being a descendant of the pin. `agree` is the recomputed hash, NAR hash
114# and root against what the ledger recorded, and it only matters when the
115# commit did not move.
116def judge(same: Bool, onward: Bool, agree: Bool, rev: String, tag: String) -> Verdict:
117 match same:
118 case True{}:
119 judge.same(agree)
120 case False{}:
121 judge.move(onward, rev, tag)
122
123# the three fields a checkout can disagree on, each required
124def agree.nar(same_nar: Bool, same_root: Bool) -> Bool:
125 match same_nar:
126 case False{}:
127 False{}
128 case True{}:
129 same_root
130
131# whether a recomputed pin is the one the ledger already recorded
132def agree.go(same_hash: Bool, same_nar: Bool, same_root: Bool) -> Bool:
133 match same_hash:
134 case False{}:
135 False{}
136 case True{}:
137 agree.nar(same_nar, same_root)
138
139# whether a recomputed pin is the one the ledger already recorded
140def agree(+oh: String, +nh: String, +onar: String, +nnar: String, +oroot: String, +nroot: String) -> Bool:
141 agree.go(String.eq(oh, nh), String.eq(onar, nnar), String.eq(oroot, nroot))
142
143# a hub miss is a different digest only when the body arrived and hashed
144# wrong. A package the hub has never seen is not that.
145def hub.bad(+why: String) -> Bool:
146 String.contains(why, "does not hash")
147
148# the dependency with a new commit written in, and the name, the entry, the
149# tag and the vendor bit left as they were
150def retarget.go(
151 +name: String,
152 +entry: String,
153 source: M.Source,
154 +rev: String,
155 +hash: String,
156 +root: String,
157 +nar: String
158) -> M.Dep:
159 match source:
160 case M.Hub{named}:
161 M.Dep{name, hash, entry, M.Hub{named}}
162 case M.Git{url, _rev, tag, _root, _nar, vend}:
163 M.Dep{name, hash, entry, M.Git{url, rev, tag, root, nar, vend}}
164
165# the dependency with a new commit written in
166def retarget(dep: M.Dep, +rev: String, +hash: String, +root: String, +nar: String) -> M.Dep:
167 M.Dep{n, _h, e, s} = dep
168 retarget.go(n, e, s, rev, hash, root, nar)
169
170# what an import line that names a package starts with: `import <hash>/`.
171# `import 0x<hash>/<file>.bend as P` is the only shape bend has, and the match
172# is exact at column 0, so an indented import is not rewritten, and neither is
173# a line that names the hash with no `/` after it.
174def reimport.head(+hash: String) -> String:
175 String.append("import ", String.append(hash, "/"))
176
177# an empty hash names no package, so it rewrites nothing
178def reimport.hit(empty: Bool, +line: String, +old: String) -> Bool:
179 match empty:
180 case True{}:
181 False{}
182 case False{}:
183 String.starts_with(line, reimport.head(old))
184
185# one line, with the branch already chosen. A match cannot scrutinise a call.
186def reimport.line.go(hit: Bool, +line: String, +old: String, +new: String) -> String:
187 match hit:
188 case True{}:
189 String.append(reimport.head(new),
190 String.drop(line, String.length(reimport.head(old))))
191 case False{}:
192 line
193
194# one line, with its import hash rewritten when the line names the old one
195def reimport.line(+line: String, +old: String, +new: String) -> String:
196 reimport.line.go(reimport.hit(String.is_empty(old), line, old), line, old, new)
197
198# one line through every replacement, in order
199def reimport.many.line(ss: List<&2, Swap>, +line: String) -> String:
200 match ss:
201 case []:
202 line
203 case Swap{+old, +new} <> t:
204 reimport.many.line(t, reimport.line(line, old, new))
205
206# every line, in order
207def reimport.many.lines(+ss: List<&2, Swap>, ls: List<&2, String>) -> List<&2, String>:
208 match ls:
209 case []:
210 []
211 case +h <> t:
212 reimport.many.line(ss, h) <> reimport.many.lines(ss, t)
213
214# a source file with every moved import hash replaced, in order. The text is
215# cut at its newlines once and joined back with them, so a line that names no
216# moved hash is left as it was, and so is the newline the file ends with, or
217# its lack of one.
218def reimport.many(+ss: List<&2, Swap>, +text: String) -> String:
219 String.join(reimport.many.lines(ss, String.lines(text)), "\n")