diff options
author | Daniel Borkmann <dborkman@redhat.com> | 2013-03-15 10:41:48 +0100 |
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committer | Daniel Borkmann <dborkman@redhat.com> | 2013-03-15 10:41:48 +0100 |
commit | 1a9fbac03c684f29cff9ac44875bd9504a89f54e (patch) | |
tree | 1b2e40dbe5dc1899ef5b62c4325c9b94c9c450fc /hash.h |
all: import netsniff-ng 0.5.8-rc0 source
We decided to get rid of the old Git history and start a new one for
several reasons:
*) Allow / enforce only high-quality commits (which was not the case
for many commits in the history), have a policy that is more close
to the one from the Linux kernel. With high quality commits, we
mean code that is logically split into commits and commit messages
that are signed-off and have a proper subject and message body.
We do not allow automatic Github merges anymore, since they are
total bullshit. However, we will either cherry-pick your patches
or pull them manually.
*) The old archive was about ~27MB for no particular good reason.
This basically derived from the bad decision that also some PDF
files where stored there. From this moment onwards, no binary
objects are allowed to be stored in this repository anymore.
The old archive is not wiped away from the Internet. You will still
be able to find it, e.g. on git.cryptoism.org etc.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Diffstat (limited to 'hash.h')
-rw-r--r-- | hash.h | 86 |
1 files changed, 86 insertions, 0 deletions
@@ -0,0 +1,86 @@ +/* + * netsniff-ng - the packet sniffing beast + * Copyright 2009, 2010 Daniel Borkmann. + * Subject to the GPL, version 2. + */ + +#ifndef HASH_H +#define HASH_H + +/* Hash table implementation from the GIT project. */ +/* Copyright 2008 (C) Linus Torvalds, GPL version 2 */ +/* + * These are some simple generic hash table helper functions. + * Not necessarily suitable for all users, but good for things + * where you want to just keep track of a list of things, and + * have a good hash to use on them. + * + * It keeps the hash table at roughly 50-75% free, so the memory + * cost of the hash table itself is roughly + * + * 3 * 2*sizeof(void *) * nr_of_objects + * + * bytes. + * + * FIXME: on 64-bit architectures, we waste memory. It would be + * good to have just 32-bit pointers, requiring a special allocator + * for hashed entries or something. + */ + +#include <stdio.h> + +#define alloc_nr(x) (((x) + 16) * 3 / 2) +#define INSERT_HASH_PROTOS(ops, table) \ + do { \ + void **pos = insert_hash((ops).key, &(ops), &(table)); \ + /* We already had an entry there? */ \ + if (pos) { \ + (ops).next = *pos; \ + *pos = &(ops); \ + } \ + } while (0) + +struct hash_table_entry { + unsigned int hash; + void *ptr; +}; + +struct hash_table { + unsigned int size, nr; + struct hash_table_entry *array; +}; + +extern void *lookup_hash(unsigned int hash, const struct hash_table *table); +extern void **insert_hash(unsigned int hash, void *ptr, + struct hash_table *table); +extern void *remove_hash(unsigned int hash, void *ptr, void *ptr_next, + struct hash_table *table); +extern int for_each_hash(const struct hash_table *table, int (*fn)(void *)); +extern int for_each_hash_int(const struct hash_table *table, + int (*fn)(void *, int), int arg); +extern void free_hash(struct hash_table *table); + +static inline void init_hash(struct hash_table *table) +{ + table->size = 0; + table->nr = 0; + table->array = NULL; +} + +static inline unsigned char icase_hash(unsigned char c) +{ + return c & ~((c & 0x40) >> 1); +} + +static inline unsigned int hash_name(const char *name, int namelen) +{ + unsigned int hash = 0x123; + do { + unsigned char c = *name++; + c = icase_hash(c); + hash = hash * 101 + c; + } while (--namelen); + return hash; +} + +#endif |