Is this gcf the whole file or is it just incomplete?

[neo644]

Ok, i am downloading CS:S for Garry's Mod using cracked steam. The download is only 21% done and in my steamapps folder i see the only file i really wanted: counter-strike source shared.gcf . The file shows as 1,719,305 KB and i can open it up in gcf explorer just fine. Is this just the file downloading or did my computer magically download a 1.6 GB file instantaneously?
Thanks in advance.