header.c (findEntry): replaced bsearch with custom routine ...
Headers normally have around 64 tags, which means bsearch will issue
6 callbacks, only to perform a single instruction (a->tag - b->tag).
This also removes a bogus piece of code.
Here is how these optimizations will impact apt. I remove
/var/cache/apt/*.bin and run "apt-cache show rpm".
4.0.4-alt100.11:
3,630,479,716 PROGRAM TOTALS
399,285,303 ???:0x0000000000033150'2 [libc-2.11.3.so]
319,106,185 ???:strlen [ld-2.11.3.so]
242,215,488 ???:pkgCache::FindPackage(char const*) [libapt-pkg-libc6.9-6.so.2.1.0]
198,711,478 ???:memcpy [ld-2.11.3.so]
198,594,999 ???:0x0000000000071970 [libc-2.11.3.so]
195,473,223 header.c:regionSwab.clone.2 [librpmdb-4.0.4.so]
135,707,034 ???:strcmp [ld-2.11.3.so]
117,134,836 header.c:dataLength [librpmdb-4.0.4.so]
102,919,244 ???:0x00000000000710f0 [libc-2.11.3.so]
102,291,091 ???:stpcpy [libc-2.11.3.so]
75,555,843 ???:bsearch [libc-2.11.3.so]
68,014,424 ???:getenv [libc-2.11.3.so]
this commit:
3,093,300,624 PROGRAM TOTALS
319,106,185 ???:strlen [ld-2.11.3.so]
242,215,488 ???:pkgCache::FindPackage(char const*) [libapt-pkg-libc6.9-6.so.2.1.0]
197,663,758 ???:0x0000000000071970 [libc-2.11.3.so]
185,771,577 header.c:regionSwab.clone.2 [librpmdb-4.0.4.so]
136,263,419 ???:strcmp [ld-2.11.3.so]
111,934,199 ???:memcpy [ld-2.11.3.so]
102,399,027 ???:0x00000000000710f0 [libc-2.11.3.so]
102,291,091 ???:stpcpy [libc-2.11.3.so]
95,231,406 header.c:dataLength [librpmdb-4.0.4.so]
76,706,744 ???:0x0000000000033150'2 [libc-2.11.3.so]
68,359,227 header.c:findEntry [librpmdb-4.0.4.so]
68,014,424 ???:getenv [libc-2.11.3.so]
a45456493b