From a0e2b28801d2ddb5ccf80a7c5d0b9ac9b75f736d Mon Sep 17 00:00:00 2001 From: Vadim Kochan Date: Fri, 5 Aug 2016 15:04:38 +0200 Subject: trafgen: proto: Use field id as array index Usually proto fields array are sorted in the same order as the respective enum. Thus, the id can be used used as an array index for faster lookup. Add an explanatory comment and enforce the correspondence of id and index using bug_on(). This will make csum field calculation a little faster at runtime. Signed-off-by: Vadim Kochan Signed-off-by: Tobias Klauser --- trafgen_l3.h | 4 ++-- trafgen_proto.c | 11 +++++------ 2 files changed, 7 insertions(+), 8 deletions(-) diff --git a/trafgen_l3.h b/trafgen_l3.h index a1b1523..e0c9a1c 100644 --- a/trafgen_l3.h +++ b/trafgen_l3.h @@ -10,14 +10,14 @@ enum ip4_field { IP4_LEN, IP4_ID, IP4_FLAGS, + IP4_MF, + IP4_DF, IP4_FRAG_OFFS, IP4_TTL, IP4_PROTO, IP4_CSUM, IP4_SADDR, IP4_DADDR, - IP4_DF, - IP4_MF, }; enum ip6_field { diff --git a/trafgen_proto.c b/trafgen_proto.c index e08c9c2..212e968 100644 --- a/trafgen_proto.c +++ b/trafgen_proto.c @@ -107,13 +107,12 @@ void proto_header_fields_add(struct proto_hdr *hdr, static struct proto_field *proto_field_by_id(struct proto_hdr *hdr, uint32_t fid) { - int i; - - for (i = 0; i < hdr->fields_count; i++) - if (hdr->fields[i].id == fid) - return &hdr->fields[i]; + /* Assume the fields are stored in the same order as the respective + * enum, so the index can be used for faster lookup here. + */ + bug_on(hdr->fields[fid].id != fid); - panic("Failed lookup field id %u for proto id %u\n", fid, hdr->id); + return &hdr->fields[fid]; } bool proto_field_is_set(struct proto_hdr *hdr, uint32_t fid) -- cgit v1.2.3-54-g00ecf href='/cgit.cgi/linux/net-next.git/tree/Documentation?id=f3d082ceabe53177c98bfa4580a294c2844966e8'>treecommitdiff
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