在PHP中可移植地检索Subversion 1.7版本？

In Subversion 1.6, there was an .svn directory in every working copy directory. I could use the following code to quickly retrive the current revision number without the need for shell access/execution.

public function getSubversionRevision() {
    if(file_exists("../.svn/entries")) {
        $svn = File("../.svn/entries");
        return (int)$svn[3];
    }
    return false;
}

Subversion 1.7 breaks this code. There is now only one .svn directory per local repository. There is an entries file in this directory but it no longer has anything useful for me. It looks like everything I need is now in a SQLite database. Specifically wc.db. I suppose I could use PHP's SQLite functions to get the info I need, but this sounds a little too expensive to run on every (or close to every) page load.

Any ideas? Breaking out the exec function and hoping that Subversion binaries are installed (and in the $PATH!) is a last resort. To summarize, I need to find a way to locate the .svn directory at the root of the repository (which could be different depending on your checkout location) and then somehow parse a file in there (probably wc.db) in a cost-effective way.

You can write a script to svn update for you every time, and scrap the revision number from the update's output into a file. The following bash script should more or less do it:

#!/bin/bash

svn --non-interactive update .. 
svn --non-interactive update .. | perl -p -e "s/.* revision ([\d]*)\./\$1/" > ../version.phtml;

try using a SVN library SVN as it will give you access to repository information and more functionality over SVN repository.
Take a look at function svn_status you will receive and array of svn repository information

Array (
    [0] => Array (
        [path] => /home/bob/wc/sandwich.txt
        [text_status] => 8 // item was modified
        [repos_text_status] => 1 // no information available, use update
        [prop_status] => 3 // no changes
        [repos_prop_status] => 1 // no information available, use update
        [name] => sandwich.txt
        [url] => http://www.example.com/svnroot/deli/trunk/sandwich.txt
        [repos] => http://www.example.com/svnroot/
        [revision] => 123 // <-- Current Revision
        //..
    )
)

I implemented a clumsy (but relatively thorough) implementation of Subversion 1.7 revision retrieval in TheHostingTool. Check the commit message for an explanation. The function is contained in class_main.php which is one directory after /trunk (/trunk/includes/class_main.php). You'll need to adjust relative paths for your specific needs. This is a slightly modified version of the function found in class_main.php for use elsewhere.

public function getSubversionRevision() {
    // This will work for Subverson 1.6 clients and below
    if(file_exists("../.svn/entries")) {
        $svn = File("../.svn/entries");
        return (int)$svn[3];
    }
    // Check the previous directories recursively looking for wc.db (Subversion 1.7)
    $searchDepth = 3; // Max search depth
    // Do we have PDO? And do we have the SQLite PDO driver?
    if(!extension_loaded('PDO') || !extension_loaded('pdo_sqlite')) {
        $searchDepth = 0; // Don't even bother...
    }
    for($i = 1; $i <= $searchDepth; $i++) {
        $dotdot .= '../';
        if(!file_exists("$dotdot.svn/wc.db")) {
            continue;
        }
        $wcdb = new PDO("sqlite:$dotdot.svn/wc.db");
        $result = $wcdb->query('SELECT "revision" FROM "NODES" WHERE "repos_path" = "'.basename(realpath('..')).'"');
        return (int)$result->fetchColumn();
    }
    if($this->canRun('exec')) {
        exec('svnversion ' . realpath('..'), $out, $return);
        // For this to work, svnversion must be in your PHP's PATH enviroment variable
        if($return === 0 && $out[0] != "Unversioned directory") {
            return (int)$out[0];
        }
    }
    return false;
}

Instead of .= '../' you may want to use str_repeat if you don't start at 1. Or, you could simply define $dotdot ahead of time to wherever you would like to start.

Or just query:

SELECT "changed_revision" FROM "NODES" ORDER BY changed_revision DESC LIMIT 1;

if you wonder the last revision of the whole repo! :)

Excuse me, but if you want portable and bullet-proof solution, why not call Subversion CLI inside PHP?

You can use svn info inside any directory of WC (capture, parse output and get a set of data) of svnversion if you want to get only global revision