make it simple, but not simpler

1 files changed, 261 insertions, 0 deletions

diff --git a/engine/mysql.php b/engine/mysql.php
new file mode 100644
index 0000000..bab8048
--- /dev/null
+++ b/engine/mysql.php
@@ -0,0 +1,261 @@
+<?php
+
+class mysql {
+
+    protected ?mysqli $link = null;
+
+    function __construct(
+        protected string $host,
+        protected string $user,
+        protected string $password,
+        protected string $database) {}
+
+    protected function prepareQuery(string $sql, ...$args): string {
+        global $config;
+        if (!empty($args)) {
+            $mark_count = substr_count($sql, '?');
+            $positions = array();
+            $last_pos = -1;
+            for ($i = 0; $i < $mark_count; $i++) {
+                $last_pos = strpos($sql, '?', $last_pos + 1);
+                $positions[] = $last_pos;
+            }
+            for ($i = $mark_count - 1; $i >= 0; $i--) {
+                $arg_val = $args[$i];
+                if (is_null($arg_val)) {
+                    $v = 'NULL';
+                } else {
+                    $v = '\''.$this->escape($arg_val) . '\'';
+                }
+                $sql = substr_replace($sql, $v, $positions[$i], 1);
+            }
+        }
+        if (!empty($config['mysql']['log']))
+            logDebug(__METHOD__.': ', $sql);
+        return $sql;
+    }
+
+    function insert(string $table, array $fields) {
+        return $this->performInsert('INSERT', $table, $fields);
+    }
+
+    function replace(string $table, array $fields) {
+        return $this->performInsert('REPLACE', $table, $fields);
+    }
+
+    protected function performInsert(string $command, string $table, array $fields) {
+        $names = [];
+        $values = [];
+        $count = 0;
+        foreach ($fields as $k => $v) {
+            $names[] = $k;
+            $values[] = $v;
+            $count++;
+        }
+
+        $sql = "{$command} INTO `{$table}` (`" . implode('`, `', $names) . "`) VALUES (" . implode(', ', array_fill(0, $count, '?')) . ")";
+        array_unshift($values, $sql);
+
+        return $this->query(...$values);
+    }
+
+    function update(string $table, array $rows, ...$cond) {
+        $fields = [];
+        $args = [];
+        foreach ($rows as $row_name => $row_value) {
+            $fields[] = "`{$row_name}`=?";
+            $args[] = $row_value;
+        }
+        $sql = "UPDATE `$table` SET ".implode(', ', $fields);
+        if (!empty($cond)) {
+            $sql .= " WHERE ".$cond[0];
+            if (count($cond) > 1)
+                $args = array_merge($args, array_slice($cond, 1));
+        }
+        return $this->query($sql, ...$args);
+    }
+
+    function multipleInsert(string $table, array $rows) {
+        list($names, $values) = $this->getMultipleInsertValues($rows);
+        $sql = "INSERT INTO `{$table}` (`".implode('`, `', $names)."`) VALUES ".$values;
+        return $this->query($sql);
+    }
+
+    function multipleReplace(string $table, array $rows) {
+        list($names, $values) = $this->getMultipleInsertValues($rows);
+        $sql = "REPLACE INTO `{$table}` (`".implode('`, `', $names)."`) VALUES ".$values;
+        return $this->query($sql);
+    }
+
+    protected function getMultipleInsertValues(array $rows): array {
+        $names = [];
+        $sql_rows = [];
+        foreach ($rows as $i => $fields) {
+            $row_values = [];
+            foreach ($fields as $field_name => $field_val) {
+                if ($i == 0) {
+                    $names[] = $field_name;
+                }
+                $row_values[] = $this->escape($field_val);
+            }
+            $sql_rows[] = "('".implode("', '", $row_values)."')";
+        }
+        return [$names, implode(', ', $sql_rows)];
+    }
+
+    function __destruct() {
+        if ($this->link)
+            $this->link->close();
+    }
+
+    function connect(): bool {
+        $this->link = new mysqli();
+        $result = $this->link->real_connect($this->host, $this->user, $this->password, $this->database);
+        if ($result)
+            $this->link->set_charset('utf8mb4');
+        return !!$result;
+    }
+
+    function query(string $sql, ...$args): mysqli_result|bool {
+        $sql = $this->prepareQuery($sql, ...$args);
+        $q = $this->link->query($sql);
+        if (!$q)
+            logError(__METHOD__.': '.$this->link->error."\n$sql\n".backtrace_as_string(1));
+        return $q;
+    }
+
+    function fetch($q): ?array {
+        $row = $q->fetch_assoc();
+        if (!$row) {
+            $q->free();
+            return null;
+        }
+        return $row;
+    }
+
+    function fetchAll($q): ?array {
+        if (!$q)
+            return null;
+        $list = [];
+        while ($f = $q->fetch_assoc()) {
+            $list[] = $f;
+        }
+        $q->free();
+        return $list;
+    }
+
+    function fetchRow($q): ?array {
+        return $q?->fetch_row();
+    }
+
+    function result($q, $field = 0) {
+        return $q?->fetch_row()[$field];
+    }
+
+    function insertId(): int {
+        return $this->link->insert_id;
+    }
+
+    function numRows($q): ?int {
+        return $q?->num_rows;
+    }
+
+    function affectedRows(): ?int {
+        return $this->link?->affected_rows;
+    }
+
+    function foundRows(): int {
+        return (int)$this->fetch($this->query("SELECT FOUND_ROWS() AS `count`"))['count'];
+    }
+
+    function escape(string $s): string {
+        return $this->link->real_escape_string($s);
+    }
+
+}
+
+class mysql_bitfield {
+
+    private GMP $value;
+    private int $size;
+
+    public function __construct($value, int $size = 64) {
+        $this->value = gmp_init($value);
+        $this->size = $size;
+    }
+
+    public function has(int $bit): bool {
+        $this->validateBit($bit);
+        return gmp_testbit($this->value, $bit);
+    }
+
+    public function set(int $bit): void {
+        $this->validateBit($bit);
+        gmp_setbit($this->value, $bit);
+    }
+
+    public function clear(int $bit): void {
+        $this->validateBit($bit);
+        gmp_clrbit($this->value, $bit);
+    }
+
+    public function isEmpty(): bool {
+        return !gmp_cmp($this->value, 0);
+    }
+
+    public function __toString(): string {
+        $buf = '';
+        for ($bit = $this->size-1; $bit >= 0; --$bit)
+            $buf .= gmp_testbit($this->value, $bit) ? '1' : '0';
+        if (($pos = strpos($buf, '1')) !== false) {
+            $buf = substr($buf, $pos);
+        } else {
+            $buf = '0';
+        }
+        return $buf;
+    }
+
+    private function validateBit(int $bit): void {
+        if ($bit < 0 || $bit >= $this->size)
+            throw new Exception('invalid bit '.$bit.', allowed range: [0..'.$this->size.')');
+    }
+
+
+}
+
+function DB(): mysql|null {
+    global $config;
+
+    /** @var ?mysql $link */
+    static $link = null;
+    if (!is_null($link))
+        return $link;
+
+    $link = new mysql(
+        $config['mysql']['host'],
+        $config['mysql']['user'],
+        $config['mysql']['password'],
+        $config['mysql']['database']);
+    if (!$link->connect()) {
+        if (!is_cli()) {
+            header('HTTP/1.1 503 Service Temporarily Unavailable');
+            header('Status: 503 Service Temporarily Unavailable');
+            header('Retry-After: 300');
+            die('database connection failed');
+        } else {
+            fwrite(STDERR, 'database connection failed');
+            exit(1);
+        }
+    }
+
+    return $link;
+}
+
+function MC(): Memcached {
+    static $mc = null;
+    if ($mc === null) {
+        $mc = new Memcached();
+        $mc->addServer("127.0.0.1", 11211);
+    }
+    return $mc;
+}