120 lines
2.6 KiB
C
120 lines
2.6 KiB
C
/*
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* Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC")
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* Copyright (C) 2000, 2001 Internet Software Consortium.
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
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* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
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* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
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* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
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* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
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* PERFORMANCE OF THIS SOFTWARE.
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*/
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/* $Id: quota.h,v 1.16 2007/06/19 23:47:18 tbox Exp $ */
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#ifndef ISC_QUOTA_H
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#define ISC_QUOTA_H 1
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/*****
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***** Module Info
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*****/
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/*! \file isc/quota.h
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*
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* \brief The isc_quota_t object is a simple helper object for implementing
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* quotas on things like the number of simultaneous connections to
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* a server. It keeps track of the amount of quota in use, and
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* encapsulates the locking necessary to allow multiple tasks to
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* share a quota.
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*/
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/***
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*** Imports.
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***/
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#include <isc/lang.h>
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#include <isc/mutex.h>
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#include <isc/types.h>
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/*****
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***** Types.
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*****/
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ISC_LANG_BEGINDECLS
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/*% isc_quota structure */
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struct isc_quota {
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isc_mutex_t lock; /*%< Locked by lock. */
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int max;
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int used;
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int soft;
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};
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isc_result_t
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isc_quota_init(isc_quota_t *quota, int max);
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/*%<
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* Initialize a quota object.
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*
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* Returns:
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* ISC_R_SUCCESS
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* Other error Lock creation failed.
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*/
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void
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isc_quota_destroy(isc_quota_t *quota);
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/*%<
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* Destroy a quota object.
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*/
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void
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isc_quota_soft(isc_quota_t *quota, int soft);
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/*%<
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* Set a soft quota.
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*/
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void
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isc_quota_max(isc_quota_t *quota, int max);
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/*%<
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* Re-set a maximum quota.
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*/
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isc_result_t
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isc_quota_reserve(isc_quota_t *quota);
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/*%<
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* Attempt to reserve one unit of 'quota'.
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*
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* Returns:
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* \li #ISC_R_SUCCESS Success
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* \li #ISC_R_SOFTQUOTA Success soft quota reached
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* \li #ISC_R_QUOTA Quota is full
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*/
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void
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isc_quota_release(isc_quota_t *quota);
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/*%<
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* Release one unit of quota.
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*/
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isc_result_t
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isc_quota_attach(isc_quota_t *quota, isc_quota_t **p);
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/*%<
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* Like isc_quota_reserve, and also attaches '*p' to the
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* quota if successful (ISC_R_SUCCESS or ISC_R_SOFTQUOTA).
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*/
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void
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isc_quota_detach(isc_quota_t **p);
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/*%<
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* Like isc_quota_release, and also detaches '*p' from the
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* quota.
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*/
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ISC_LANG_ENDDECLS
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#endif /* ISC_QUOTA_H */
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