Never the less if the high-pressure hose (SPG) or a low-pressure hose (e.g. primary 2nd stage, secondary 2nd stage) leaks you will loose breathing gas and should finish the dive.
The time til all your remaining breathing gas has left the tank depends on the size of the hole. Let’s asume the hose is fully leaking based on a cut through the hose.
If a high-pressure hose leaks that way it will take quite a while til you’re out of air because of that. The reason for it is that the borehole of the connector of the hose has a size of a needlepoint.
That’s different with the low-pressure hoses. If one of them leaks that way you will loose your breathing gas way faster. It’s because the borehole of the connector of these hoses is way bigger.
If you are deeper down the gas will leave slightly slower, cause the ambient pressure is higher. Never the less the impact in recreational depths isn’t worth to mention. (Comment from Rick Murchison)