diff options
Diffstat (limited to 'thirdparty/openssl/crypto/lhash')
-rw-r--r-- | thirdparty/openssl/crypto/lhash/lhash.c | 77 |
1 files changed, 48 insertions, 29 deletions
diff --git a/thirdparty/openssl/crypto/lhash/lhash.c b/thirdparty/openssl/crypto/lhash/lhash.c index f20353aea3..51bb258e74 100644 --- a/thirdparty/openssl/crypto/lhash/lhash.c +++ b/thirdparty/openssl/crypto/lhash/lhash.c @@ -101,6 +101,24 @@ #include <openssl/crypto.h> #include <openssl/lhash.h> +/* + * A hashing implementation that appears to be based on the linear hashing + * alogrithm: + * https://en.wikipedia.org/wiki/Linear_hashing + * + * Litwin, Witold (1980), "Linear hashing: A new tool for file and table + * addressing", Proc. 6th Conference on Very Large Databases: 212-223 + * http://hackthology.com/pdfs/Litwin-1980-Linear_Hashing.pdf + * + * From the wikipedia article "Linear hashing is used in the BDB Berkeley + * database system, which in turn is used by many software systems such as + * OpenLDAP, using a C implementation derived from the CACM article and first + * published on the Usenet in 1988 by Esmond Pitt." + * + * The CACM paper is available here: + * https://pdfs.semanticscholar.org/ff4d/1c5deca6269cc316bfd952172284dbf610ee.pdf + */ + const char lh_version[] = "lhash" OPENSSL_VERSION_PTEXT; #undef MIN_NODES @@ -108,7 +126,7 @@ const char lh_version[] = "lhash" OPENSSL_VERSION_PTEXT; #define UP_LOAD (2*LH_LOAD_MULT) /* load times 256 (default 2) */ #define DOWN_LOAD (LH_LOAD_MULT) /* load times 256 (default 1) */ -static void expand(_LHASH *lh); +static int expand(_LHASH *lh); static void contract(_LHASH *lh); static LHASH_NODE **getrn(_LHASH *lh, const void *data, unsigned long *rhash); @@ -182,8 +200,9 @@ void *lh_insert(_LHASH *lh, void *data) void *ret; lh->error = 0; - if (lh->up_load <= (lh->num_items * LH_LOAD_MULT / lh->num_nodes)) - expand(lh); + if (lh->up_load <= (lh->num_items * LH_LOAD_MULT / lh->num_nodes) + && !expand(lh)) + return NULL; rn = getrn(lh, data, &hash); @@ -300,19 +319,37 @@ void lh_doall_arg(_LHASH *lh, LHASH_DOALL_ARG_FN_TYPE func, void *arg) doall_util_fn(lh, 1, (LHASH_DOALL_FN_TYPE)0, func, arg); } -static void expand(_LHASH *lh) +static int expand(_LHASH *lh) { LHASH_NODE **n, **n1, **n2, *np; - unsigned int p, i, j; - unsigned long hash, nni; + unsigned int p, pmax, nni, j; + unsigned long hash; + + nni = lh->num_alloc_nodes; + p = lh->p; + pmax = lh->pmax; + if (p + 1 >= pmax) { + j = nni * 2; + n = OPENSSL_realloc(lh->b, (int)(sizeof(LHASH_NODE *) * j)); + if (n == NULL) { + lh->error++; + return 0; + } + lh->b = n; + memset(n + nni, 0, sizeof(*n) * (j - nni)); + lh->pmax = nni; + lh->num_alloc_nodes = j; + lh->num_expand_reallocs++; + lh->p = 0; + } else { + lh->p++; + } lh->num_nodes++; lh->num_expands++; - p = (int)lh->p++; n1 = &(lh->b[p]); - n2 = &(lh->b[p + (int)lh->pmax]); - *n2 = NULL; /* 27/07/92 - eay - undefined pointer bug */ - nni = lh->num_alloc_nodes; + n2 = &(lh->b[p + pmax]); + *n2 = NULL; for (np = *n1; np != NULL;) { #ifndef OPENSSL_NO_HASH_COMP @@ -330,25 +367,7 @@ static void expand(_LHASH *lh) np = *n1; } - if ((lh->p) >= lh->pmax) { - j = (int)lh->num_alloc_nodes * 2; - n = (LHASH_NODE **)OPENSSL_realloc(lh->b, - (int)(sizeof(LHASH_NODE *) * j)); - if (n == NULL) { - lh->error++; - lh->num_nodes--; - lh->p = 0; - return; - } - /* else */ - for (i = (int)lh->num_alloc_nodes; i < j; i++) /* 26/02/92 eay */ - n[i] = NULL; /* 02/03/92 eay */ - lh->pmax = lh->num_alloc_nodes; - lh->num_alloc_nodes = j; - lh->num_expand_reallocs++; - lh->p = 0; - lh->b = n; - } + return 1; } static void contract(_LHASH *lh) |