cat-file: speed up default format

eb54a3391b (cat-file: skip expanding default format, 2022-03-15) added special handling for the default batch format. In the meantime it has fallen behind the code path for handling arbitrary formats. Bring it up to speed by using the new and more efficient strbuf_add_oid_hex() and strbuf_add_uint() instead of strbuf_addf(): Benchmark 1: ./git_main cat-file --batch-all-objects --batch-check='%(objectname) %(objecttype) %(objectsize)' Time (mean ± σ): 1.051 s ± 0.003 s [User: 1.027 s, System: 0.023 s] Range (min … max): 1.049 s … 1.058 s 10 runs Benchmark 2: ./git_main cat-file --batch-all-objects --batch-check='%(objectname)-%(objecttype)-%(objectsize)' Time (mean ± σ): 1.012 s ± 0.002 s [User: 0.988 s, System: 0.023 s] Range (min … max): 1.010 s … 1.018 s 10 runs Benchmark 3: ./git cat-file --batch-all-objects --batch-check='%(objectname) %(objecttype) %(objectsize)' Time (mean ± σ): 979.0 ms ± 1.1 ms [User: 954.1 ms, System: 23.2 ms] Range (min … max): 977.7 ms … 980.8 ms 10 runs Summary ./git cat-file --batch-all-objects --batch-check='%(objectname) %(objecttype) %(objectsize)' ran 1.03 ± 0.00 times faster than ./git_main cat-file --batch-all-objects --batch-check='%(objectname)-%(objecttype)-%(objectsize)' 1.07 ± 0.00 times faster than ./git_main cat-file --batch-all-objects --batch-check='%(objectname) %(objecttype) %(objectsize)' Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>