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Diffstat (limited to 'src/core/objhash.h')
| -rw-r--r-- | src/core/objhash.h | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/src/core/objhash.h b/src/core/objhash.h new file mode 100644 index 00000000..e6fef50a --- /dev/null +++ b/src/core/objhash.h @@ -0,0 +1,57 @@ +// +// Copyright 2016 Garrett D'Amore <garrett@damore.org> +// +// This software is supplied under the terms of the MIT License, a +// copy of which should be located in the distribution where this +// file was obtained (LICENSE.txt). A copy of the license may also be +// found online at https://opensource.org/licenses/MIT. +// + +#ifndef CORE_OBJHASH_H +#define CORE_OBJHASH_H + +#include "core/nng_impl.h" + +// Object Hash. This is a generic object manager, which lets us deal +// with reference counting of objects, and provides a unique ID for +// objects that will not generally be reused. Object Hash manages it's +// own locking. Object IDs start from a random positive value, and +// generally increment. The ID assigned to an object will always be +// positive. +// +// Similar to our linked lists, consumers must supply a node structure +// in their object. The implementation uses this for reference counting +// and so forth. +// +// In terms of implementation, the underlying hash uses open addressing, +// combined with an improved probe (taken from Python) to avoid collisions. +// Our algorithm just uses the low order bits, and we use table sizes that +// are powers of two to make the modulo dirt cheap. +// + +typedef struct nni_objhash nni_objhash; +typedef struct nni_objhash_node nni_objhash_node; + +// Object constructor function. This is expected to allocate an object. +// It takes the generated object ID as an argument, which it can store on +// the object itself. It should return NULL if resources cannot be allocated; +// there are no other valid reasons for this to fail. +typedef void *(*nni_objhash_ctor)(uint32_t); + +// Object destructor function. This should release any resources and perform +// any other deinitialization. +typedef void (*nni_objhash_dtor)(void *); + +// nni_objhash_init initializes the object hash; the constructor and and +// destructor functions are supplied. +extern int nni_objhash_init(nni_objhash **, nni_objhash_ctor, nni_objhash_dtor); + +extern void nni_objhash_fini(nni_objhash *); +extern void nni_objhash_reclaim(nni_objhash *); + +extern int nni_objhash_find(nni_objhash *, uint32_t, void **); +extern void nni_objhash_unref(nni_objhash *, uint32_t); +extern int nni_objhash_alloc(nni_objhash *, uint32_t *, void **); +extern size_t nni_objhash_count(nni_objhash *); + +#endif // CORE_OBJHASH_H |