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@jboner
jboner / latency.txt
Last active November 14, 2025 11:14
Latency Numbers Every Programmer Should Know
Latency Comparison Numbers (~2012)
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L1 cache reference 0.5 ns
Branch mispredict 5 ns
L2 cache reference 7 ns 14x L1 cache
Mutex lock/unlock 25 ns
Main memory reference 100 ns 20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy 3,000 ns 3 us
Send 1K bytes over 1 Gbps network 10,000 ns 10 us
Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD
@codebutler
codebutler / JsonHelper.java
Created April 8, 2012 20:20
Convert Android JSONObject/JSONArray to a standard Map/List.
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.*;
public class JsonHelper {
public static Object toJSON(Object object) throws JSONException {
if (object instanceof Map) {
JSONObject json = new JSONObject();
@andrewgleave
andrewgleave / iOSMapKitFitAnnotations.m
Last active May 17, 2024 02:07
Zooms out a MKMapView to enclose all its annotations (inc. current location)
MKMapRect zoomRect = MKMapRectNull;
for (id <MKAnnotation> annotation in mapView.annotations) {
MKMapPoint annotationPoint = MKMapPointForCoordinate(annotation.coordinate);
MKMapRect pointRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0, 0);
if (MKMapRectIsNull(zoomRect)) {
zoomRect = pointRect;
} else {
zoomRect = MKMapRectUnion(zoomRect, pointRect);
}
}