LibreNMS/LibreNMS/DB/Schema.php

308 lines
8.8 KiB
PHP

<?php
/**
* Schema.php
*
* Class for querying the schema
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* @package LibreNMS
* @link http://librenms.org
* @copyright 2018 Tony Murray
* @author Tony Murray <murraytony@gmail.com>
*/
namespace LibreNMS\DB;
use LibreNMS\Config;
use LibreNMS\Util\Version;
use Symfony\Component\Yaml\Yaml;
use \Schema as LaravelSchema;
class Schema
{
private static $relationship_blacklist = [
'devices_perms',
'bill_perms',
'ports_perms',
];
private $relationships;
private $schema;
/**
* Check the database to see if the migrations have all been run
*
* @return bool
*/
public static function isCurrent()
{
if (LaravelSchema::hasTable('migrations')) {
return self::getMigrationFiles()->diff(self::getAppliedMigrations())->isEmpty();
}
return false;
}
/**
* Check for extra migrations and return them
*
* @return \Illuminate\Support\Collection
*/
public static function getUnexpectedMigrations()
{
return self::getAppliedMigrations()->diff(self::getMigrationFiles());
}
/**
* @return \Illuminate\Support\Collection
*/
private static function getMigrationFiles()
{
$migrations = collect(glob(base_path('database/migrations/') . '*.php'))
->map(function ($migration_file) {
return basename($migration_file, '.php');
});
return $migrations;
}
/**
* @return \Illuminate\Support\Collection
*/
private static function getAppliedMigrations()
{
return Eloquent::DB()->table('migrations')->pluck('migration');
}
/**
* Get the primary key column(s) for a table
*
* @param string $table
* @return string|array if a single column just the name is returned, otherwise an array of column names
*/
public function getPrimaryKey($table)
{
$schema = $this->getSchema();
$columns = $schema[$table]['Indexes']['PRIMARY']['Columns'];
if (count($columns) == 1) {
return reset($columns);
}
return $columns;
}
public function getSchema()
{
if (!isset($this->schema)) {
$file = Config::get('install_dir') . '/misc/db_schema.yaml';
$this->schema = Yaml::parse(file_get_contents($file));
}
return $this->schema;
}
/**
* Get a list of all tables.
*
* @return array
*/
public function getTables()
{
return array_keys($this->getSchema());
}
/**
* Return all columns for the given table
*
* @param $table
* @return array
*/
public function getColumns($table)
{
$schema = $this->getSchema();
return array_column($schema[$table]['Columns'], 'Field');
}
/**
* Get all relationship paths.
* Caches the data after the first call as long as the schema hasn't changed
*
* @param string $base
* @return mixed
*/
public function getAllRelationshipPaths($base = 'devices')
{
$update_cache = true;
$cache_file = Config::get('install_dir') . "/cache/{$base}_relationships.cache";
$db_version = Version::get()->database();
if (is_file($cache_file)) {
$cache = unserialize(file_get_contents($cache_file));
if ($cache['version'] == $db_version) {
$update_cache = false; // cache is valid skip update
}
}
if ($update_cache) {
$paths = [];
foreach ($this->getTables() as $table) {
$path = $this->findPathRecursive([$table], $base);
if ($path) {
$paths[$table] = $path;
}
}
$cache = [
'version' => $db_version,
$base => $paths
];
file_put_contents($cache_file, serialize($cache));
}
return $cache[$base];
}
/**
* Find the relationship path from $start to $target
*
* @param string $target
* @param string $start Default: devices
* @return array|false list of tables in path order, or false if no path is found
*/
public function findRelationshipPath($target, $start = 'devices')
{
d_echo("Searching for target: $start, starting with $target\n");
if ($target == $start) {
// um, yeah, we found it...
return [$start];
}
$all = $this->getAllRelationshipPaths($start);
return isset($all[$target]) ? $all[$target] : false;
}
private function findPathRecursive(array $tables, $target, $history = [])
{
$relationships = $this->getTableRelationships();
d_echo("Starting Tables: " . json_encode($tables) . PHP_EOL);
if (!empty($history)) {
$tables = array_diff($tables, $history);
d_echo("Filtered Tables: " . json_encode($tables) . PHP_EOL);
}
foreach ($tables as $table) {
// check for direct relationships
if (in_array($table, $relationships[$target])) {
d_echo("Direct relationship found $target -> $table\n");
return [$table, $target];
}
$table_relations = $relationships[$table] ?? [];
d_echo("Searching $table: " . json_encode($table_relations) . PHP_EOL);
if (!empty($table_relations)) {
if (in_array($target, $relationships[$table])) {
d_echo("Found in $table\n");
return [$target, $table]; // found it
} else {
$recurse = $this->findPathRecursive($relationships[$table], $target, array_merge($history, $tables));
if ($recurse) {
return array_merge($recurse, [$table]);
}
}
} else {
$relations = array_keys(array_filter($relationships, function ($related) use ($table) {
return in_array($table, $related);
}));
d_echo("Dead end at $table, searching for relationships " . json_encode($relations) . PHP_EOL);
$recurse = $this->findPathRecursive($relations, $target, array_merge($history, $tables));
if ($recurse) {
return array_merge($recurse, [$table]);
}
}
}
return false;
}
public function getTableRelationships()
{
if (!isset($this->relationships)) {
$schema = $this->getSchema();
$relations = array_column(array_map(function ($table, $data) {
$columns = array_column($data['Columns'], 'Field');
$related = array_filter(array_map(function ($column) use ($table) {
$guess = $this->getTableFromKey($column);
if ($guess != $table) {
return $guess;
}
return null;
}, $columns));
// renumber $related array
$related = array_values($related);
return [$table, $related];
}, array_keys($schema), $schema), 1, 0);
// filter out blacklisted tables
$this->relationships = array_diff_key($relations, array_flip(self::$relationship_blacklist));
}
return $this->relationships;
}
public function getTableFromKey($key)
{
if (ends_with($key, '_id')) {
// hardcoded
if ($key == 'app_id') {
return 'applications';
}
// try to guess assuming key_id = keys table
$guessed_table = substr($key, 0, -3);
if (!ends_with($guessed_table, 's')) {
if (ends_with($guessed_table, 'x')) {
$guessed_table .= 'es';
} else {
$guessed_table .= 's';
}
}
if (array_key_exists($guessed_table, $this->getSchema())) {
return $guessed_table;
}
}
return null;
}
public function columnExists($table, $column)
{
return in_array($column, $this->getColumns($table));
}
}