General aviation aircraft in the pattern at LVK experienced conflict with traffic entering downwind; reporter questioned tower procedure and services provided.

Narrative

Sun high in sky; visibility 20 miles; ceiling unlimited; distant haze. Tower has an unobstructed view of runway/traffic pattern's and radar. Directed by Tower to enter a left base for the left runway; Tower then advised there was another airplane in the pattern without radio contact. Did that mean; prior arrangement; light; signals? Later someone apologized for being on the wrong frequency. Landed; taxied back; takeoff; stay in pattern; land; had done about 5 circuits when Tower told me that traffic was inbound from San Jose and I acknowledged. I was turning from crosswind to downwind when an airplane passed underneath by about 20 FT; possibly the San Jose traffic? No other traffic advisories; he turned right to a downwind; had he decided to join the pattern from the juncture of the crosswind and downwind instead of 'abeam the midpoint of the runway' per AIM? I continue left turn to the downwind. This began diatribes from the Tower; next to impossible trying to communicate. 1) Asked did I see the other aircraft? Saw TOO well; now almost in front of me. Wish I had had a radar update. Conflict usually is resolved by the Tower routing the arriving traffic. Usually seamless. 2) Directed me to follow the other aircraft; which I was already doing. But it was far too close; so moved to outside and above; slowed for normal spacing; both aircraft completed a normal landing. 3) Said that MY downwind was too far out. This airport is closed in by homes/noise abatement at each end. The published airport diagram clearly shows this and space is needed for a normal departure and landing. If the Tower felt that an adjustment was really needed then why didn't he advise me of this some time during my previous 5 circuits? The aircraft were passing from right to left directly in from of him! Did this 5 times. When the Controller became upset he didn't pause long enough between words for a response; happened several times. I acknowledged all that I could. The Tower; between loose traffic and near midair; did not seem very collected.