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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)/* Copyright (c) 2021 Facebook */#include <stdint.h>#include <stdlib.h>#include <stdio.h>#include <errno.h>#include <linux/err.h>#include "hashmap.h"#include "libbpf_internal.h"#include "strset.h"
struct strset { void *strs_data; size_t strs_data_len; size_t strs_data_cap; size_t strs_data_max_len;
/* lookup index for each unique string in strings set */ struct hashmap *strs_hash;};
static size_t strset_hash_fn(long key, void *ctx){ const struct strset *s = ctx; const char *str = s->strs_data + key;
return str_hash(str);}
static bool strset_equal_fn(long key1, long key2, void *ctx){ const struct strset *s = ctx; const char *str1 = s->strs_data + key1; const char *str2 = s->strs_data + key2;
return strcmp(str1, str2) == 0;}
struct strset *strset__new(size_t max_data_sz, const char *init_data, size_t init_data_sz){ struct strset *set = calloc(1, sizeof(*set)); struct hashmap *hash; int err = -ENOMEM;
if (!set) return ERR_PTR(-ENOMEM);
hash = hashmap__new(strset_hash_fn, strset_equal_fn, set); if (IS_ERR(hash)) goto err_out;
set->strs_data_max_len = max_data_sz; set->strs_hash = hash;
if (init_data) { long off;
set->strs_data = malloc(init_data_sz); if (!set->strs_data) goto err_out;
memcpy(set->strs_data, init_data, init_data_sz); set->strs_data_len = init_data_sz; set->strs_data_cap = init_data_sz;
for (off = 0; off < set->strs_data_len; off += strlen(set->strs_data + off) + 1) { /* hashmap__add() returns EEXIST if string with the same * content already is in the hash map */ err = hashmap__add(hash, off, off); if (err == -EEXIST) continue; /* duplicate */ if (err) goto err_out; } }
return set;err_out: strset__free(set); return ERR_PTR(err);}
void strset__free(struct strset *set){ if (IS_ERR_OR_NULL(set)) return;
hashmap__free(set->strs_hash); free(set->strs_data); free(set);}
size_t strset__data_size(const struct strset *set){ return set->strs_data_len;}
const char *strset__data(const struct strset *set){ return set->strs_data;}
static void *strset_add_str_mem(struct strset *set, size_t add_sz){ return libbpf_add_mem(&set->strs_data, &set->strs_data_cap, 1, set->strs_data_len, set->strs_data_max_len, add_sz);}
static long strset_str_append(struct strset *set, const char *s){ uintptr_t old_data = (uintptr_t)set->strs_data; size_t old_data_len = set->strs_data_len; uintptr_t old_s = (uintptr_t)s; long len = strlen(s) + 1; void *p;
/* * Hashmap keys are always offsets within set->strs_data, so to even * look up some string from the "outside", we need to first append it * at the end, so that it can be addressed with an offset. Luckily, * until set->strs_data_len is incremented, that string is just a piece * of garbage for the rest of the code, so no harm, no foul. On the * other hand, if the string is unique, it's already appended and * ready to be used, only a simple set->strs_data_len increment away. */ p = strset_add_str_mem(set, len); if (!p) return -ENOMEM;
/* * The set->strs_data might have reallocated and if 's' pointed * to an internal string within the old buffer, then it became * dangling and needs to be reconstructed before the copy. */ if (old_data && old_data != (uintptr_t)set->strs_data && old_s >= old_data && old_s < old_data + old_data_len) s = set->strs_data + (old_s - old_data);
memcpy(p, s, len);
return len;}
/* Find string offset that corresponds to a given string *s*. * Returns: * - >0 offset into string data, if string is found; * - -ENOENT, if string is not in the string data; * - <0, on any other error. */int strset__find_str(struct strset *set, const char *s){ long old_off, new_off, len;
len = strset_str_append(set, s); if (len < 0) return len;
new_off = set->strs_data_len;
if (hashmap__find(set->strs_hash, new_off, &old_off)) return old_off;
return -ENOENT;}
/* Add a string s to the string data. If the string already exists, return its * offset within string data. * Returns: * - > 0 offset into string data, on success; * - < 0, on error. */int strset__add_str(struct strset *set, const char *s){ long old_off, new_off, len; int err;
len = strset_str_append(set, s); if (len < 0) return len;
new_off = set->strs_data_len;
/* Now attempt to add the string, but only if the string with the same * contents doesn't exist already (HASHMAP_ADD strategy). If such * string exists, we'll get its offset in old_off (that's old_key). */ err = hashmap__insert(set->strs_hash, new_off, new_off, HASHMAP_ADD, &old_off, NULL); if (err == -EEXIST) return old_off; /* duplicated string, return existing offset */ if (err) return err;
set->strs_data_len += len; /* new unique string, adjust data length */ return new_off;}