tests/test-sqlitestore.t

dirstate-tree: Add tree traversal/iteration

Like Python’s, Rust’s iterators are "external" in that they are driven
by a caller who calls a `next` method. This is as opposed to "internal"
iterators who drive themselves and call a callback for each item.

Writing an internal iterator traversing a tree is easy with recursion,
but internal iterators cannot rely on the call stack in that way,
they must save in an explicit object all state that they need to be
preserved across two `next` calls.

This algorithm uses a `Vec` as a stack that contains what would be
local variables on the call stack if we could use recursion.

Differential Revision: https://phab.mercurial-scm.org/D10370

#require sqlite no-chg

The sqlitestore backend leaves transactions around when used with chg.
Since this backend is primarily intended as proof-of-concept for
alternative storage backends, disable it for chg test runs to avoid
the instability.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > sqlitestore =
  > EOF

New repo should not use SQLite by default

  $ hg init empty-no-sqlite
  $ cat empty-no-sqlite/.hg/requires
  dotencode
  fncache
  generaldelta
  persistent-nodemap (rust !)
  revlog-compression-zstd (zstd !)
  revlogv1
  sparserevlog
  store

storage.new-repo-backend=sqlite is recognized

  $ hg --config storage.new-repo-backend=sqlite init empty-sqlite
  $ cat empty-sqlite/.hg/requires
  dotencode
  exp-sqlite-001
  exp-sqlite-comp-001=zstd (zstd !)
  exp-sqlite-comp-001=$BUNDLE2_COMPRESSIONS$ (no-zstd !)
  fncache
  generaldelta
  persistent-nodemap (rust !)
  revlog-compression-zstd (zstd !)
  revlogv1
  sparserevlog
  store

  $ cat >> $HGRCPATH << EOF
  > [storage]
  > new-repo-backend = sqlite
  > EOF

Can force compression to zlib

  $ hg --config storage.sqlite.compression=zlib init empty-zlib
  $ cat empty-zlib/.hg/requires
  dotencode
  exp-sqlite-001
  exp-sqlite-comp-001=$BUNDLE2_COMPRESSIONS$
  fncache
  generaldelta
  persistent-nodemap (rust !)
  revlog-compression-zstd (zstd !)
  revlogv1
  sparserevlog
  store

Can force compression to none

  $ hg --config storage.sqlite.compression=none init empty-none
  $ cat empty-none/.hg/requires
  dotencode
  exp-sqlite-001
  exp-sqlite-comp-001=none
  fncache
  generaldelta
  persistent-nodemap (rust !)
  revlog-compression-zstd (zstd !)
  revlogv1
  sparserevlog
  store

Can make a local commit

  $ hg init local-commit
  $ cd local-commit
  $ echo 0 > foo
  $ hg commit -A -m initial
  adding foo

That results in a row being inserted into various tables

  $ sqlite3 .hg/store/db.sqlite -init /dev/null << EOF
  > SELECT * FROM filepath;
  > EOF
  1|foo

  $ sqlite3 .hg/store/db.sqlite -init /dev/null << EOF
  > SELECT * FROM fileindex;
  > EOF
  1|1|0|-1|-1|0|0|1||6/\xef(L\xe2\xca\x02\xae\xcc\x8d\xe6\xd5\xe8\xa1\xc3\xaf\x05V\xfe (esc)

  $ sqlite3 .hg/store/db.sqlite -init /dev/null << EOF
  > SELECT * FROM delta;
  > EOF
  1|1|	\xd2\xaf\x8d\xd2"\x01\xdd\x8dH\xe5\xdc\xfc\xae\xd2\x81\xff\x94"\xc7|0 (esc)
  

Tracking multiple files works

  $ echo 1 > bar
  $ hg commit -A -m 'add bar'
  adding bar

  $ sqlite3 .hg/store/db.sqlite -init /dev/null << EOF
  > SELECT * FROM filedata ORDER BY id ASC;
  > EOF
  1|1|foo|0|6/\xef(L\xe2\xca\x02\xae\xcc\x8d\xe6\xd5\xe8\xa1\xc3\xaf\x05V\xfe|-1|-1|0|0|1| (esc)
  2|2|bar|0|\xb8\xe0/d3s\x80!\xa0e\xf9Au\xc7\xcd#\xdb_\x05\xbe|-1|-1|1|0|2| (esc)

Multiple revisions of a file works

  $ echo a >> foo
  $ hg commit -m 'modify foo'

  $ sqlite3 .hg/store/db.sqlite -init /dev/null << EOF
  > SELECT * FROM filedata ORDER BY id ASC;
  > EOF
  1|1|foo|0|6/\xef(L\xe2\xca\x02\xae\xcc\x8d\xe6\xd5\xe8\xa1\xc3\xaf\x05V\xfe|-1|-1|0|0|1| (esc)
  2|2|bar|0|\xb8\xe0/d3s\x80!\xa0e\xf9Au\xc7\xcd#\xdb_\x05\xbe|-1|-1|1|0|2| (esc)
  3|1|foo|1|\xdd\xb3V\xcd\xde1p@\xf7\x8e\x90\xb8*\x8b,\xe9\x0e\xd6j+|0|-1|2|0|3|1 (esc)

  $ cd ..