silverstripe-framework/core/manifest/ConfigManifest.php
2012-04-15 10:50:19 +12:00

494 lines
17 KiB
PHP

<?php
/**
* A utility class which builds a manifest of configuration items
*
* @package sapphire
* @subpackage manifest
*/
class SS_ConfigManifest {
/** @var array All the values needed to be collected to determine the correct combination of fragements for the current environment. */
protected $variantKeySpec = array();
/** @var array All the _config.php files. Need to be included every request & can't be cached. Not variant specific. */
protected $phpConfigSources = array();
/** @var array All the _config/*.yml fragments pre-parsed and sorted in ascending include order. Not variant specific. */
protected $yamlConfigFragments = array();
/** @var array The calculated config from _config/*.yml, sorted, filtered and merged. Variant specific. */
public $yamlConfig = array();
/** @var array A side-effect of collecting the _config fragments is the calculation of all module directories, since the definition
* of a module is "a directory that contains either a _config.php file or a _config directory */
public $modules = array();
/** Adds a path as a module */
function addModule($path) {
$module = basename($path);
if (isset($this->modules[$module]) && $this->modules[$module] != $path) {
user_error("Module ".$module." in two places - ".$path." and ".$this->modules[$module]);
}
$this->modules[$module] = $path;
}
/** Returns true if the passed module exists */
function moduleExists($module) {
return array_key_exists($module, $this->modules);
}
/**
* Constructs and initialises a new configuration object, either loading
* from the cache or re-scanning for classes.
*
* @param string $base The project base path.
* @param bool $forceRegen Force the manifest to be regenerated.
*/
public function __construct($base, $includeTests = false, $forceRegen = false ) {
$this->base = $base;
// Get the Zend Cache to load/store cache into
$this->cache = SS_Cache::factory('SS_Configuration', 'Core', array(
'automatic_serialization' => true,
'lifetime' => null
));
// Unless we're forcing regen, try loading from cache
if (!$forceRegen) {
// The PHP config sources are always needed
$this->phpConfigSources = $this->cache->load('php_config_sources');
// Get the variant key spec - if this isn't present, we can't figure out what variant we're in so it's full regen time
if ($this->variantKeySpec = $this->cache->load('variant_key_spec')) {
// Try getting the pre-filtered & merged config for this variant
if (!($this->yamlConfig = $this->cache->load('yaml_config_'.$this->variantKey()))) {
// Otherwise, if we do have the yaml config fragments (and we should since we have a variant key spec) work out the config for this variant
if ($this->yamlConfigFragments = $this->cache->load('yaml_config_fragments')) {
$this->buildYamlConfigVariant();
}
}
}
}
// If we don't have a config yet, we need to do a full regen to get it
if (!$this->yamlConfig) {
$this->regenerate($includeTests);
$this->buildYamlConfigVariant();
}
}
/**
* Includes all of the php _config.php files found by this manifest. Called by SS_Config when adding this manifest
* @return void
*/
public function activateConfig() {
foreach ($this->phpConfigSources as $config) {
require_once $config;
}
}
/**
* Returns the string that uniquely identifies this variant. The variant is the combination of classes, modules, environment,
* environment variables and constants that selects which yaml fragments actually make it into the configuration because of "only"
* and "except" rules.
*
* @return string
*/
public function variantKey() {
$key = $this->variantKeySpec; // Copy to fill in actual values
if (isset($key['environment'])) $key['environment'] = Director::isDev() ? 'dev' : (Director::isTest() ? 'test' : 'live');
if (isset($key['envvars'])) foreach ($key['envvars'] as $variable => $foo) {
$key['envvars'][$variable] = isset($_ENV[$variable]) ? $_ENV[$variable] : null;
}
if (isset($key['constants'])) foreach ($key['constants'] as $variable => $foo) {
$key['constants'][$variable] = defined($variable) ? constant($variable) : null;
}
return sha1(serialize($key));
}
/**
* Completely regenerates the manifest file. Scans through finding all php _config.php and yaml _config/*.ya?ml files,
* parses the yaml files into fragments, sorts them and figures out what values need to be checked to pick the
* correct variant.
*
* Does _not_ build the actual variant
*
* @param bool $cache Cache the result.
*/
public function regenerate($includeTests = false, $cache = true) {
$finder = new ManifestFileFinder();
$finder->setOptions(array(
'name_regex' => '/_config.php$/',
'ignore_tests' => !$includeTests,
'file_callback' => array($this, 'addSourceConfigFile')
));
$finder->find($this->base);
$finder = new ManifestFileFinder();
$finder->setOptions(array(
'name_regex' => '/\.ya?ml$/',
'ignore_tests' => !$includeTests,
'file_callback' => array($this, 'addYAMLConfigFile')
));
$finder->find($this->base);
$this->prefilterYamlFragments();
$this->sortYamlFragments();
$this->buildVariantKeySpec();
if ($cache) {
$this->cache->save($this->phpConfigSources, 'php_config_sources');
$this->cache->save($this->yamlConfigFragments, 'yaml_config_fragments');
$this->cache->save($this->variantKeySpec, 'variant_key_spec');
}
}
/**
* Handle finding a php file. We just keep a record of all php files found, we don't include them
* at this stage
*
* Public so that ManifestFileFinder can call it. Not for general use.
*/
public function addSourceConfigFile($basename, $pathname, $depth) {
$this->phpConfigSources[] = $pathname;
// Add this module too
$this->addModule(dirname($pathname));
}
/**
* Handle finding a yml file. Parse the file by spliting it into header/fragment pairs,
* and normalising some of the header values (especially: give anonymous name if none assigned,
* splt/complete before and after matchers)
*
* Public so that ManifestFileFinder can call it. Not for general use.
*/
public function addYAMLConfigFile($basename, $pathname, $depth) {
if (!preg_match('{/([^/]+)/_config/}', $pathname, $match)) return;
// Keep track of all the modules we've seen
$this->addModule(dirname(dirname($pathname)));
// We use Symfony Yaml since it's the most complete. It still doesn't handle all of YAML, but it's better than
// nothing.
require_once 'thirdparty/symfony-yaml/lib/sfYamlParser.php';
$parser = new sfYamlParser();
// The base header
$base = array(
'module' => $match[1],
'file' => basename(basename($basename, '.yml'), '.yaml')
);
// YAML parsers really should handle this properly themselves, but neither spyc nor symfony-yaml do. So we
// follow in their vein and just do what we need, not what the spec says
$parts = preg_split('/^---$/m', file_get_contents($pathname), -1, PREG_SPLIT_NO_EMPTY);
// If only one document, it's a headerless fragment. So just add it with an anonymous name
if (count($parts) == 1) {
$this->yamlConfigFragments[] = $base + array(
'name' => 'anonymous-1',
'fragment' => $parser->parse($parts[0])
);
}
// Otherwise it's a set of header/document pairs
else {
// If we got an odd number of parts the config file doesn't have a header for every document
if (count($parts) % 2 != 0) user_error("Configuration file $basename does not have an equal number of headers and config blocks");
// Step through each pair
for ($i = 0; $i < count($parts); $i+=2) {
// Make all the first-level keys of the header lower case
$header = array_change_key_case($parser->parse($parts[$i]), CASE_LOWER);
// Assign a name if non assigned already
if (!isset($header['name'])) $header['name'] = 'anonymous-'.(1+$i/2);
// Parse & normalise the before and after if present
foreach (array('before', 'after') as $order) {
if (isset($header[$order])) {
// First, splice into parts (multiple before or after parts are allowed, comma separated)
$orderparts = preg_split('/\s+,\s+/', $header[$order], PREG_SPLIT_NO_EMPTY);
// For each, parse out into module/file#name, and set any missing to "*"
$header[$order] = array();
foreach($orderparts as $part) {
preg_match('! (\*|\w+) (?:\/(\*|\w+) (?:\*|\#(\w+))? )? !x', $part, $match);
$header[$order][] = array(
'module' => $match[1],
'file' => isset($match[2]) ? $match[2] : '*',
'name' => isset($match[3]) ? $match[3] : '*'
);
}
}
}
// And add to the fragments list
$this->yamlConfigFragments[] = $base + $header + array(
'fragment' => $parser->parse($parts[$i+1])
);
}
}
}
/**
* Sorts the YAML fragments so that the "before" and "after" rules are met.
* Throws an error if there's a loop
*
* We can't use regular sorts here - we need a topological sort. Easiest
* way is with a DAG, so build up a DAG based on the before/after rules, then
* sort that.
*
* @return void
*/
protected function sortYamlFragments() {
$frags = $this->yamlConfigFragments;
// Build a directed graph
$dag = new SS_DAG($frags);
foreach ($frags as $i => $frag) {
foreach ($frags as $j => $otherfrag) {
if ($i == $j) continue;
$order = $this->relativeOrder($frag, $otherfrag);
if ($order == 'before') $dag->addedge($i, $j);
elseif ($order == 'after') $dag->addedge($j, $i);
}
}
$this->yamlConfigFragments = $dag->sort();
}
/**
* Return a string "after", "before" or "undefined" depending on whether the YAML fragment array element passed as $a should
* be positioned after, before, or either compared to the YAML fragment array element passed as $b
*
* @param $a Array - a YAML config fragment as loaded by addYAMLConfigFile
* @param $b Array - a YAML config fragment as loaded by addYAMLConfigFile
* @return string "after", "before" or "undefined"
*/
protected function relativeOrder($a, $b) {
$matchesSomeRule = array();
// Do the same thing for after and before
foreach (array('after'=>'before', 'before'=>'after') as $rulename => $opposite) {
$matchesSomeRule[$rulename] = false;
// If no rule specified, we don't match it
if (isset($a[$rulename])) {
foreach ($a[$rulename] as $rule) {
$matchesRule = true;
foreach(array('module', 'file', 'name') as $part) {
$partMatches = true;
// If part is *, we match _unless_ the opposite rule has a non-* matcher than also matches $b
if ($rule[$part] == '*') {
if (isset($a[$opposite])) foreach($a[$opposite] as $oppositeRule) {
if ($oppositeRule[$part] == $b[$part]) { $partMatches = false; break; }
}
}
else {
$partMatches = ($rule[$part] == $b[$part]);
}
$matchesRule = $matchesRule && $partMatches;
if (!$matchesRule) break;
}
$matchesSomeRule[$rulename] = $matchesSomeRule[$rulename] || $matchesRule;
}
}
}
// Check if it matches both rules - problem if so
if ($matchesSomeRule['before'] && $matchesSomeRule['after']) {
user_error('Config fragment requires itself to be both before _and_ after another fragment', E_USER_ERROR);
}
return $matchesSomeRule['before'] ? 'before' : ($matchesSomeRule['after'] ? 'after' : 'undefined');
}
/**
* This function filters the loaded yaml fragments, removing any that can't ever have their "only" and "except" rules
* match
*
* Some tests in "only" and "except" rules need to be checked per request, but some are manifest based -
* these are invariant over requests and only need checking on manifest rebuild. So we can prefilter these before
* saving yamlConfigFragments to speed up the process of checking the per-request variant/
*/
function prefilterYamlFragments() {
$matchingFragments = array();
foreach ($this->yamlConfigFragments as $i => $fragment) {
$failsonly = isset($fragment['only']) && !$this->matchesPrefilterVariantRules($fragment['only']);
$matchesexcept = isset($fragment['except']) && $this->matchesPrefilterVariantRules($fragment['except']);
if (!$failsonly && !$matchesexcept) $matchingFragments[] = $fragment;
}
$this->yamlConfigFragments = $matchingFragments;
}
/**
* Returns false if the prefilterable parts of the rule aren't met, and true if they are
*
* @param $rules array - A hash of rules as allowed in the only or except portion of a config fragment header
* @return bool - True if the rules are met, false if not. (Note that depending on whether we were passed an only or an except rule,
* which values means accept or reject a fragment
*/
function matchesPrefilterVariantRules($rules) {
foreach ($rules as $k => $v) {
switch (strtolower($k)) {
case 'classexists':
if (!ClassInfo::exists($v)) return false;
break;
case 'moduleexists':
if (!$this->moduleExists($v)) return false;
break;
default:
// NOP
}
}
return true;
}
/**
* Builds the variant key spec - the list of values that need to be build to give a key that uniquely identifies this variant.
*/
function buildVariantKeySpec() {
$this->variantKeySpec = array();
foreach ($this->yamlConfigFragments as $fragment) {
if (isset($fragment['only'])) $this->addVariantKeySpecRules($fragment['only']);
if (isset($fragment['except'])) $this->addVariantKeySpecRules($fragment['except']);
}
}
/**
* Adds any variables referenced in the passed rules to the $this->variantKeySpec array
*/
function addVariantKeySpecRules($rules) {
foreach ($rules as $k => $v) {
switch (strtolower($k)) {
case 'classexists':
case 'moduleexists':
// Classes and modules are a special case - we can pre-filter on config regenerate because we already know
// if the class or module exists
break;
case 'environment':
$this->variantKeySpec['environment'] = true;
break;
case 'envvarset':
if (!isset($this->variantKeySpec['envvars'])) $this->variantKeySpec['envvars'] = array();
$this->variantKeySpec['envvars'][$k] = $k;
break;
case 'constantdefined':
if (!isset($this->variantKeySpec['constants'])) $this->variantKeySpec['constants'] = array();
$this->variantKeySpec['constants'][$k] = $k;
break;
default:
if (!isset($this->variantKeySpec['envvars'])) $this->variantKeySpec['envvars'] = array();
if (!isset($this->variantKeySpec['constants'])) $this->variantKeySpec['constants'] = array();
$this->variantKeySpec['envvars'][$k] = $this->variantKeySpec['constants'][$k] = $k;
}
}
}
/**
* Calculates which yaml config fragments are applicable in this variant, and merge those all together into
* the $this->yamlConfig propperty
*/
function buildYamlConfigVariant($cache = true) {
$this->yamlConfig = array();
foreach ($this->yamlConfigFragments as $i => $fragment) {
$failsonly = isset($fragment['only']) && !$this->matchesVariantRules($fragment['only']);
$matchesexcept = isset($fragment['except']) && $this->matchesVariantRules($fragment['except']);
if (!$failsonly && !$matchesexcept) $this->mergeInYamlFragment($this->yamlConfig, $fragment['fragment']);
}
if ($cache) {
$this->cache->save($this->yamlConfig, 'yaml_config_'.$this->variantKey());
}
}
/**
* Returns false if the non-prefilterable parts of the rule aren't met, and true if they are
*/
function matchesVariantRules($rules) {
foreach ($rules as $k => $v) {
switch (strtolower($k)) {
case 'classexists':
case 'moduleexists':
break;
case 'environment':
switch (strtolower($v)) {
case 'live':
if (!Director::isLive()) return false;
break;
case 'test':
if (!Director::isTest()) return false;
break;
case 'dev':
if (!Director::isDev()) return false;
break;
default:
user_error('Unknown environment '.$v.' in config fragment', E_USER_ERROR);
}
break;
case 'envvarset':
if (isset($_ENV[$k])) break;
return false;
case 'constantdefined':
if (defined($k)) break;
return false;
default:
if (isset($_ENV[$k]) && $_ENV[$k] == $v) break;
if (defined($k) && constant($k) == $v) break;
return false;
}
}
return true;
}
/**
* Recursively merge a yaml fragment's configuration array into the primary merged configuration array.
* @param $into
* @param $fragment
* @return void
*/
function mergeInYamlFragment(&$into, $fragment) {
foreach ($fragment as $k => $v) {
if (is_array($v) || is_object($v)) {
if (isset($into[$k])) { $sub = $into[$k]; $this->mergeInYamlFragment($sub, $v); $into[$k] = $sub; }
else $into[$k] = $v;
}
else if (is_numeric($k)) $into[] = $v;
else $into[$k] = $v;
}
}
}