|
1
|
|
|
<?php |
|
2
|
|
|
/** |
|
3
|
|
|
* Server-side cache for recommendation provider API |
|
4
|
|
|
* |
|
5
|
|
|
* Construct a ApiCache object by passing an array of all parameters that |
|
6
|
|
|
* uniquely identifies the request. The array will be serialized then base64 |
|
7
|
|
|
* encoded to generate a cache filename that can be easily referenced later. |
|
8
|
|
|
* |
|
9
|
|
|
* Calling the get() generator will either yield data from cache, or proxied |
|
10
|
|
|
* and automatically cached data via the provided generator closure. |
|
11
|
|
|
* |
|
12
|
|
|
* Cache files are newline seperated data chunks to be yielded. |
|
13
|
|
|
* The first line is reserved for the timestamp the cache was created. |
|
14
|
|
|
* |
|
15
|
|
|
* By default, all caches live for 1 hour. This can be overriden by |
|
16
|
|
|
* instantiating an ApiCache instance, and setting the cacheExpires property. |
|
17
|
|
|
* |
|
18
|
|
|
* @author National Research Council |
|
19
|
|
|
* @author Luc Belliveau |
|
20
|
|
|
* @link http://www.nrc-cnrc.gc.ca/eng/rd/dt/ NRC Digital Technologies |
|
21
|
|
|
* |
|
22
|
|
|
* @license MIT |
|
23
|
|
|
* @copyright Her Majesty the Queen in Right of Canada, as represented by the Minister of National Research Council, 2019 |
|
24
|
|
|
*/ |
|
25
|
|
|
|
|
26
|
|
|
namespace NRC; |
|
27
|
|
|
|
|
28
|
|
|
class ApiCache { |
|
29
|
|
|
// Filename to store cache into |
|
30
|
|
|
private $cacheFile = NULL; |
|
31
|
|
|
|
|
32
|
|
|
// Location to store cache files, must end with a trailing / |
|
33
|
|
|
public $cacheFolder = NULL; |
|
34
|
|
|
|
|
35
|
|
|
// Number of seconds cache is valid. Default is 3600 seconds, or 1 hour. |
|
36
|
|
|
public $cacheExpires = 3600; |
|
37
|
|
|
|
|
38
|
|
|
function __construct($signature) { |
|
39
|
|
|
$this->cacheFolder = sys_get_temp_dir() . '/nrc-api-cache/'; |
|
40
|
|
|
if (!file_exists($this->cacheFolder)) { |
|
41
|
|
|
mkdir($this->cacheFolder); |
|
42
|
|
|
} |
|
43
|
|
|
$this->cacheFile = base64_encode(json_encode($signature)); |
|
44
|
|
|
} |
|
45
|
|
|
|
|
46
|
|
|
/** |
|
47
|
|
|
* Get the requested cache, or call the callback $cb to seed it. |
|
48
|
|
|
* |
|
49
|
|
|
* @param Closure $cb generator |
|
50
|
|
|
*/ |
|
51
|
|
|
public function get($cb) { |
|
52
|
|
|
$cached = false; |
|
53
|
|
|
$filename = $this->cacheFolder . $this->cacheFile; |
|
54
|
|
|
|
|
55
|
|
|
if (file_exists($filename)) { |
|
56
|
|
|
$fp = fopen($filename, 'r'); |
|
57
|
|
|
$cacheTime = (int)fgets($fp); |
|
58
|
|
|
if ($cacheTime < (time() + $this->cacheExpires)) { |
|
59
|
|
|
$cached = true; |
|
60
|
|
|
fpassthru($fp); |
|
61
|
|
|
// while (($buffer = fgets($fp, 4096)) !== false) { |
|
62
|
|
|
// yield $buffer; |
|
63
|
|
|
// } |
|
64
|
|
|
} |
|
65
|
|
|
fclose($fp); |
|
66
|
|
|
} |
|
67
|
|
|
if (!$cached) { |
|
68
|
|
|
$fp = fopen($filename, 'w'); |
|
69
|
|
|
fwrite($fp, time() . "\n"); |
|
70
|
|
|
$data = $cb(); |
|
71
|
|
|
while ($data->valid()) { |
|
72
|
|
|
$output = $data->current(); |
|
73
|
|
|
fwrite($fp, $output); |
|
74
|
|
|
yield $output; |
|
75
|
|
|
$data->next(); |
|
76
|
|
|
} |
|
77
|
|
|
fclose($fp); |
|
78
|
|
|
} |
|
79
|
|
|
} |
|
80
|
|
|
} |
gctools-outilsgc /
gcconnex
