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Update SCAN example code

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Ivan Tanev
2016-01-31 12:25:35 +02:00
parent f7f3e9a0b1
commit 545e7231ab
1 changed files with 21 additions and 8 deletions
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29
examples/scan.js
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@@ -15,6 +15,27 @@ function scan() {
// Update the cursor position for the next scan
cursor = res[0];
// get the SCAN result for this iteration
var keys = res[1];
// Remember: more or less than COUNT or no keys may be returned
// See http://redis.io/commands/scan#the-count-option
// Also, SCAN may return the same key multiple times
// See http://redis.io/commands/scan#scan-guarantees
// Additionally, you should always have the code that uses the keys
// before the code checking the cursor.
if (keys.length > 0) {
console.log('Array of matching keys', keys);
}
// It's important to note that the cursor and returned keys
// vary independently. The scan is never complete until redis
// returns a non-zero cursor. However, with MATCH and large
// collections, most iterations will return an empty keys array.
// Still, a cursor of zero DOES NOT mean that there are no keys.
// A zero cursor just means that the SCAN is complete, but there
// might be one last batch of results to process.
// From <http://redis.io/commands/scan>:
// 'An iteration starts when the cursor is set to 0,
@@ -22,14 +43,6 @@ function scan() {
if (cursor === '0') {
return console.log('Iteration complete');
}
// Remember: more or less than COUNT or no keys may be returned
// See http://redis.io/commands/scan#the-count-option
// Also, SCAN may return the same key multiple times
// See http://redis.io/commands/scan#scan-guarantees
if (res[1].length > 0) {
console.log('Array of matching keys', res[1]);
}
return scan();
}