exchange: move code for consuming streaming clone into exchange For reasons outlined in the previous commit, we want to make the code for consuming "stream bundles" reusable. This patch extracts the code into a standalone function.

exchange: move code for generating a streaming clone into exchange Streaming clones are fast because they are essentially tar files. On mozilla-central, a streaming clone only consumes ~55s CPU time on clients as opposed to ~340s CPU time for a regular clone or gzip bundle unbundle. Mozilla is deploying static file "lookaside" support to our Mercurial server. Static bundles are pre-generated and uploaded to S3. When a clone is performed, the static file is fetched, applied, and then an incremental pull is performed. Unfortunately, on an ideal network connection this still takes as much wall and CPU time as a regular clone (although it does save significant server resources). We like the client-side wall time wins of streaming clones. But we want to leverage S3-based pre-generated files for serving the bulk of clone data. This patch moves the code for producing a "stream bundle" into its own standalone function, away from the wire protocol. This will enable stream bundle files to be produced outside the context of the wire protocol. A bikeshed on whether exchange is the best module for this function might be warranted. I selected exchange instead of changegroup because "stream bundles" aren't changegroups (yet).

dirstate: avoid match.files() in walk()

match: introduce boolean prefix() method tl;dr: This is another step towards a (previously unstated) goal of eliminating match.files() in conditions. There are four types of matchers: * always: Matches everything, checked with always(), files() is empty * exact: Matches exact set of files, checked with isexact(), files() contains the files to match * patterns: Matches more complex patterns, checked with anypats(), files() contains roots of the matched patterns * prefix: Matches simple 'path:' patterns as prefixes ('foo' matches both 'foo' and 'foo/bar'), no single method to check, files() contains the prefixes to match For completeness, it would be nice to have a method for checking for the "prefix" type of matcher as well, so let's add that, making it return True simply when none of the others do. The larger goal here is to eliminate uses of match.files() in conditions (i.e. bool(match.files())). The reason for this is that there are scenarios when you would like to create a "prefix" matcher that happens to match no files. One example is for 'hg files -I foo bar'. The narrowmatcher also restricts the set of files given and it would not surprise me if have bugs caused by that already. Note that 'if m.files() and not m.anypats()' and similar is sometimes used to catch the "exact" and "prefix" cases above.

hgweb: descend empty directories in monoblue The ability to "skip" a chain of empty directories in hgweb was added in c21d236ca897, but monoblue style wasn't updated. This block is copied from gitweb/map file and just works.

match: have visitdir() consider includes and excludes match.visitdir() used to only look at the match's primary pattern roots to decide if a treemanifest traverser should descend into a particular directory. This change logically makes visitdir also consider the match's include and exclude pattern roots (if applicable) to make this decision. This is especially important for situations like using narrowhg with multiple treemanifest revlogs.

hgweb: remove artificial width constraint from header in monoblue This width property comes from the beginning of the monoblue theme itself, and was used to stop the action header ("summary", "shortlog", "changelog", etc) from clashing with the search form. But it still was happening (on smaller screens, and with more actions added to hgweb over time). Effectively, the hardcoded width was preventing the header from fitting into the available screen space, since it always tried to be 900px wide, even if that meant horizontal scroll on smaller screens and having the actions on two lines where one should've been enough. For example, http://selenic.com/hg/log?style=monoblue has the last two actions ("gz" and "help") in the header on the second line, even when there seems to be enough space on the first. This patch makes the form float, which prevents it from overlaying/clashing with the action header, and allows the latter to resize itself in the best possible way.

merge with stable

files: recurse into subrepos automatically with an explicit path

dirstate: use open/read of vfs(opener) explicitly instead of read This simplifies changes in subsequent patch, which tries to open `.pending` file when HG_PENDING environment variable is defined.