The most exciting
features of PHP 7.1
by Enrico Zimuel
Senior Software Engineer
Zend, a Rogue Wave Company (USA)
PHPDay 2017, Verona, 12th May
About me
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PHP 7.1
- 7.1.0 released (01 Dec 2016)
- Latest is 7.1.5 (11 May 2017)
7.1 by numbers
- 376 bug fixes
- 12 new features
- 13 new functions
- 36 new global constants
- 20 backward incompatible changes
- 2 deprecated features
- 16 changed functions
- 7 other changes
New features
Nullable types
- For parameters and return values
- Prefixing the type name with a ?
- NULL can be passed as an argument,
or returned as a value
Example
function hi(?string $name): ?string
{
if (null === $name) {
return null;
}
return 'Hello ' . $name;
}
echo hi(null); // returns null
echo hi('Enrico'); // returns 'Hello Enrico'
echo hi(); // Fatal error: Too few arguments to function hi(), 0 passed
OOP Example
interface Fooable {
function foo(): ?Fooable;
}
interface StrictFooable extends Fooable {
function foo(): Fooable; // valid
}
interface Fooable {
function foo(): Fooable;
}
interface LooseFooable extends Fooable {
function foo(): ?Fooable; // invalid
}
OOP Example (2)
interface Fooable {
function foo(Fooable $f);
}
interface LooseFoo extends Fooable {
function foo(?Fooable $f); // valid
}
interface Fooable {
function foo(?Fooable $f);
}
interface StrictFoo extends Fooable {
function foo(Fooable $f); // invalid
}
Void Return Type
function swap(&$left, &$right): void
{
if ($left === $right) {
return;
}
$tmp = $left;
$left = $right;
$right = $tmp;
}
$a = 1;
$b = 2;
var_dump(swap($a, $b), $a, $b); // null, int(2), int(1)
Array destructuring
$data = [
['foo', 'bar', 'baz']
];
[$a, $b] = $data[0];
var_dump($a, $b); // string(3) "foo", string(3) "bar"
[$a, , $c] = $data[0];
var_dump($a, $c); // string(3) "foo", string(3) "baz"
foreach ($data as [$a, $b, $c]) {
var_dump($a, $b, $c);
// string(3) "foo"
// string(3) "bar"
// string(3) "baz"
}
Support for keys
Specify keys in list(), or its new shorthand [] syntax
$data = [
'a' => 'foo',
'b' => 'bar',
'c' => 'baz'
];
list('a' => $a, 'b' => $b, 'c' => $c) = $data;
var_dump($a, $b, $c);
// string(3) "foo"
// string(3) "bar"
// string(3) "baz"
['a' => $a, 'b' => $b, 'c' => $c] = $data;
var_dump($a, $b, $c);
// string(3) "foo"
// string(3) "bar"
// string(3) "baz"
No mix list() and [ ]
// Not allowed
list([$a, $b], [$c, $d]) = [[1, 2], [3, 4]];
[list($a, $b), list($c, $d)] = [[1, 2], [3, 4]];
// Allowed
list(list($a, $b), list($c, $d)) = [[1, 2], [3, 4]];
[[$a, $b], [$c, $d]] = [[1, 2], [3, 4]];
Iterable
- Added the iterable pseudo-type
- It accepts array or Traversable
- Can be used in parameter and return types
Example
function foo(iterable $iterable): void
{
foreach ($iterable as $value) {
var_dump($value);
}
}
foo([1,2,3]);
foo(new ArrayIterator([1,2,3]));
Class CONST visibility
class ConstDemo
{
const PUBLIC_CONST_A = 1; // default to public
public const PUBLIC_CONST_B = 2;
protected const PROTECTED_CONST = 3;
private const PRIVATE_CONST = 4;
}
Using Reflection
$obj = new ReflectionClass("ConstDemo");
foreach ($obj->getReflectionConstants() as $const) {
var_dump($const); // object(ReflectionClassConstant)
var_dump($const->getName());
var_dump($const->getValue());
var_dump($const->isPublic());
var_dump($const->isPrivate());
var_dump($const->isProtected());
}
ReflectionClassConstant is not documented (BUG #74261)
Multiple catch {}
try {
// Some code...
} catch (ExceptionType1 $e) {
// Code to handle the exception
} catch (ExceptionType2 $e) {
// Same code to handle the exception
} catch (Exception $e) {
// ...
}
try {
// Some code...
} catch (ExceptionType1 | ExceptionType2 $e) {
// Code to handle the exception
} catch (\Exception $e) {
// ...
}
Negative string offsets
var_dump("abcdef"[-2]); // string(1) "e"
var_dump("abcdef"[-7]); // string(0) "", PHP Notice offset
// strpos
var_dump(strpos("aabbcc", "b", -3)); // int(3)
// get the last character of a string
$last = substr($foo, -1); // before PHP 7.1
$last = $foo[-1];
Async signal handling
pcntl_async_signals() has been introduced to enable asynchronous signal handling without using ticks
pcntl_async_signals(true); // turn on async signals
pcntl_signal(SIGHUP, function($sig) {
echo "SIGHUP\n";
});
posix_kill(posix_getpid(), SIGHUP);
Closure from callable
class Test
{
public function exposeFunction()
{
return Closure::fromCallable([$this, 'privateFunction']);
}
private function privateFunction($param)
{
var_dump($param);
}
}
$privFunc = (new Test)->exposeFunction();
var_dump($privFunc); // object(Closure)
$privFunc('some value'); // string(10) "some value"
OpenSSL AEAD
Authenticated Encrypt with Associated Data (AEAD)
Support GCM and CCM encryption modes
GCM is 3x faster than CCM. See this benchmark
More info on Authenticated Encryption in PHP 7.1
openssl_encrypt()
string openssl_encrypt(
string $data,
string $method,
string $password,
[ int $options = 0 ],
[ string $iv = "" ],
[ string &$tag = NULL ],
[ string $aad = "" ],
[ int $tag_length = 16 ]
)
$tag contains the authentication hash
openssl_decrypt()
string openssl_decrypt(
string $data,
string $method,
string $password,
[ int $options = 0 ],
[ string $iv = "" ],
[ string $tag = "" ],
[ string $aad = "" ]
)
$tag is the authentication hash
Encrypt example
$algo = 'aes-256-gcm';
$iv = random_bytes(openssl_cipher_iv_length($algo));
$key = random_bytes(32); // 256 bit
$data = random_bytes(1024); // 1 Kb of random data
$ciphertext = openssl_encrypt(
$data,
$algo,
$key,
OPENSSL_RAW_DATA,
$iv,
$tag
);
// output is $ciphertext and $tag
$tag is the authentication hash
Decrypt example
$decrypt = openssl_decrypt(
$ciphertext,
$algo,
$key,
OPENSSL_RAW_DATA,
$iv,
$tag
);
if (false === $decrypt) {
throw new Exception(sprintf(
"OpenSSL error: %s", openssl_error_string()
));
}
printf ("Decryption %s\n", $data === $decrypt ? 'Ok' : 'Failed');
$tag is the authentication hash
HTTP/2 Server Push
- Server push has been added to CURL 7.46+
- Use curl_multi_setopt() function with the new CURLMOPT_PUSHFUNCTION constant
- Added CURL_PUSH_OK and CURL_PUSH_DENY to approve or deny the callback execution
Example
$transfers = 1;
$callback = function($parent_ch, $pushed_ch, array $headers)
use (&$transfers) {
$transfers++;
return CURL_PUSH_OK;
};
$mh = curl_multi_init();
curl_multi_setopt($mh, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
curl_multi_setopt($mh, CURLMOPT_PUSHFUNCTION, $callback);
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://localhost:8080/index.html");
curl_setopt($ch, CURLOPT_HTTP_VERSION, 3);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0); // self-signed cert
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0); // self-signed cert
curl_multi_add_handle($mh, $ch);
Example (2)
$active = null;
do {
$status = curl_multi_exec($mh, $active);
do {
$info = curl_multi_info_read($mh);
if (false !== $info && $info['msg'] == CURLMSG_DONE) {
$handle = $info['handle'];
if ($handle !== null) {
$transfers--; // decrement remaining requests
$body = curl_multi_getcontent($info['handle']);
curl_multi_remove_handle($mh, $handle);
curl_close($handle);
}
}
} while ($info);
} while ($transfers);
curl_multi_close($mh);
New hash functions
Added hash_hkdf() function to support HKDF (RFC 5869)
$key = random_bytes(32);
$salt = random_bytes(16);
$encryptKey = hash_hkdf('sha256', $key, 32, 'encrypt', $salt);
$authKey = hash_hkdf('sha256', $key, 32, 'auth', $salt);
var_dump($encryptKey !== $authKey); // bool(true)
Added SHA3 support (224, 256, 384, and 512)
$hash = hash('sha3-224', 'This is a text');
var_dump($hash);
// string(56)"9209f5869ad03ac11549902b3c83fe8e6b7e1cd1614ab4291587db43"
To summarize
- Nullable and void return types
- Array destructuring
- Iterable
- Class CONST visibility
- Multiple catch {}
- Async signal handling
- Closure from callable
- OpenSSL AEAD
- HTTP/2 Server Push
- New hash functions
Thanks!
Rate this talk at https://joind.in/talk/935fc
Contact me: enrico.zimuel [at] roguewave.com
Follow me: @ezimuel
This work is licensed under a
Creative Commons Attribution-ShareAlike 3.0 Unported License.
I used reveal.js to make this presentation.