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LibrePilot/flight/libraries/PyMite/vm/seglist.h

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/*
# This file is Copyright 2003, 2006, 2007, 2009, 2010 Dean Hall.
#
# This file is part of the PyMite VM.
# The PyMite VM is free software: you can redistribute it and/or modify
# it under the terms of the GNU GENERAL PUBLIC LICENSE Version 2.
#
# The PyMite VM is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# A copy of the GNU GENERAL PUBLIC LICENSE Version 2
# is seen in the file COPYING in this directory.
*/
#ifndef __SEGLIST_H__
#define __SEGLIST_H__
/**
* \file
* \brief Segmented List data structure
*
* A seglist is a linked list of segments.
* A segment is an array of ptrs to objects
* (with a pointer to the next segment).
* Seglists are used to implement Lists and Dicts.
*
* This implementation of Seglist is straight.
* That is, the next pointer in the final segment
* contains C_NULL.
*
* This implementation of Seglist is dense.
* That is, there are no gaps in a segment.
* All entries point to an object, except entries
* that are beyond the index of the last item.
*/
/** Defines the length of the object array in a segment */
#define SEGLIST_OBJS_PER_SEG 8
/** Segment - an array of ptrs to objs */
typedef struct Segment_s
{
/** object descriptor */
PmObjDesc_t od;
/** array of ptrs to objs */
pPmObj_t s_val[SEGLIST_OBJS_PER_SEG];
/** ptr to next segment */
struct Segment_s *next;
} Segment_t,
*pSegment_t;
/** Seglist - linked list of segments with current index info */
typedef struct Seglist_s
{
/** object descriptor */
PmObjDesc_t od;
/** ptr to first segment in list */
pSegment_t sl_rootseg;
/** ptr to last segment */
pSegment_t sl_lastseg;
/** index of (one past) last obj in last segment */
int16_t sl_length;
} Seglist_t,
*pSeglist_t;
/**
* Puts the new object at the end of the list.
* This is intended for the List type where
* the List index matches the order of the Seglist index.
* Makes room if necessary by adding new segments.
*
* @param pseglist Ptr to seglist
* @param pobj Pointer to object to append
* @return Return status
*/
PmReturn_t seglist_appendItem(pSeglist_t pseglist, pPmObj_t pobj);
/**
* Clears the the seglist by unlinking the root segment.
*
* @param pseglist Ptr to seglist to empty
*/
PmReturn_t seglist_clear(pSeglist_t pseglist);
/**
* Finds the first obj equal to pobj in the seglist.
* Starts searching the list at the given segnum and indx.
*
* @param pseglist The seglist to search
* @param pobj The object to match
* @param r_index Return arg; the index of where to start the search.
* If a match is found, return the index by reference.
* If no match is found, this value is undefined.
* @return Return status; PM_RET_OK means a matching object
* was found. PM_RET_ERR otherwise.
*/
PmReturn_t seglist_findEqual(pSeglist_t pseglist,
pPmObj_t pobj, int16_t *r_index);
/**
* Gets the item in the seglist at the given coordinates.
* The segment number and the index within the segment
* are the coordinates of the object to get.
*
* @param pseglist Ptr to seglist to scan
* @param index Index of item to get
* @param r_pobj Return arg; Ptr to object at the index
* @return Return status; PM_RET_OK if object found.
* PM_RET_ERR otherwise.
*/
PmReturn_t seglist_getItem(pSeglist_t pseglist,
int16_t index, pPmObj_t *r_pobj);
/**
* Allocates a new empty seglist
*
* @param r_pseglist return; Address of ptr to new seglist
* @return Return status
*/
PmReturn_t seglist_new(pSeglist_t *r_pseglist);
/**
* Puts the item in the next available slot in the first available segment.
* This is intended for the Dict type where
* the Seglist index is insignificant.
* Pushing an object assures it will be found early
* during a call to seglist_findEqual().
*
* @param pseglist Ptr to seglist in which object is placed.
* @param pobj Ptr to object which is inserted.
* @param index Index into seglist before which item is inserted
* @return Return status; PM_RET_OK if the item was inserted.
* Any error condition comes from heap_getChunk.
*/
PmReturn_t seglist_insertItem(pSeglist_t pseglist,
pPmObj_t pobj, int16_t index);
/**
* Puts the item in the designated slot and segment.
* This is intended to be used after seglist_findEqual()
* returns the proper indeces.
*
* @param pseglist Ptr to seglist in which object is placed.
* @param pobj Ptr to object which is set.
* @param index Index into seglist of where to put object.
* @return Return status; PM_RET_OK if object is set.
* PM_RET_ERR otherwise.
*/
PmReturn_t seglist_setItem(pSeglist_t pseglist, pPmObj_t pobj, int16_t index);
/**
* Removes the item at the given index.
*
* @param pseglist Ptr to seglist in which object is removed.
* @param index Index into seglist of where to put object.
* @return Return status
*/
PmReturn_t seglist_removeItem(pSeglist_t pseglist, uint16_t index);
#endif /* __SEGLIST_H__ */