[ https://issues.apache.org/jira/browse/TS-4316?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Alan M. Carroll updated TS-4316: -------------------------------- Fix Version/s: (was: 7.0.0) sometime > Slot accelerator doesn't effect under certain condition > ------------------------------------------------------- > > Key: TS-4316 > URL: https://issues.apache.org/jira/browse/TS-4316 > Project: Traffic Server > Issue Type: Bug > Components: MIME > Reporter: Masakazu Kitajo > Assignee: Alan M. Carroll > Fix For: sometime > > > Slot accelerators seem to not effect if the stored slot number is 14 or 15. > This is because {{mime_hdr_set_accelerators_and_presence_bits()}} regards > slot number 14+ as "unknown" and stores MIME_FIELD_SLOTNUM_UNKNOWN(14) to an > accelerator, and it causes slower search. Although there is no critical > effect, it would decreases performance slightly. > The numbers, 14 and 15, comes from constants below in MIME.h: > {code} > #define MIME_FIELD_SLOTNUM_BITS 4 > #define MIME_FIELD_SLOTNUM_MASK ((1 << MIME_FIELD_SLOTNUM_BITS) - 1) > #define MIME_FIELD_SLOTNUM_MAX (MIME_FIELD_SLOTNUM_MASK - 1) > #define MIME_FIELD_SLOTNUM_UNKNOWN MIME_FIELD_SLOTNUM_MAX > {code} > MIME_FIELD_SLOTNUM_MASK is 15. > MIME_FIELD_SLOTNUM_MAX is 14. > MIME_FIELD_SLOTNUM_UNKNOWN is 14 too. > Though it still needs more careful confirmation, it seems we can simply > change {{MIME_FIELD_SLOTNUM_UNKNOWN}} to the value of > {{MIME_FIELD_SLOTNUM_MASK}} (15). But we still cannot use 15. > To use 15 as a valid slot number in slot accelerators, we need to change > {{MIME_FIELD_SLOTNUM_UNKNOWN}} to 16 or -1, however it would need to change > some codes also (not only the number). > This bug has been found while I was tackling TS-4313. > https://github.com/apache/trafficserver/pull/542#discussion-diff-58226891 -- This message was sent by Atlassian JIRA (v6.3.4#6332)