cmHashTbl.h/c : Initial commit.

This commit is contained in:
kevin 2014-01-25 16:13:57 -05:00
parent f95d93a4f8
commit 9b3aa4c798
2 changed files with 531 additions and 0 deletions

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#include "cmGlobal.h"
#include "cmFloatTypes.h"
#include "cmRpt.h"
#include "cmErr.h"
#include "cmCtx.h"
#include "cmMem.h"
#include "cmLinkedHeap.h"
#include "cmMallocDebug.h"
#include "cmMath.h"
#include "cmHashTbl.h"
#include "cmText.h"
enum
{
kFreeHtFl = 0x01,
};
typedef struct cmHtValue_str
{
unsigned flags; // See kXXXHtFl above.
unsigned id; // unique id associated with this value
void* value; // value blob
unsigned byteCnt; // size of value blob in bytes
struct cmHtValue_str* link; // cmHtBucket_t.list link
} cmHtValue_t;
typedef struct
{
cmHtValue_t* list; // value list
cmHtValue_t* avail; // available value slots - formed from cmHashTblRemoved() values.
unsigned nextIdx; // next unused index for this bucket
} cmHtBucket_t;
typedef struct
{
cmErr_t err;
cmLHeapH_t lhH; // memory for hash table buckets, values, value blobs.
unsigned bucketCnt; // hash table bucket cnt
unsigned linkCnt; // max length of collision list for each bucket
unsigned mask; // hash id bucket index mask (masks the MSB's of the hash-id)
unsigned maskShift; // shift required to move the lowest 'mask' bit to the LSB.
cmHtBucket_t* b; // b[bucketCnt] bucket array
} cmHt_t;
cmHashTblH_t cmHashTblNullHandle = cmSTATIC_NULL_HANDLE;
#define _cmHtBucketIndex( p, id ) (((id) & (p)->mask) >> (p)->maskShift)
cmHt_t* _cmHtHandleToPtr( cmHashTblH_t h )
{
cmHt_t* p = (cmHt_t*)h.h;
assert(p!=NULL);
return p;
}
// Return the bucket index portion of the hash id.
unsigned _cmHtGenId( cmHt_t* p, const void* v, unsigned byteCnt )
{
unsigned i,j;
const char* cv = v;
unsigned h = 0;
for(i=0,j=3; i<byteCnt; ++i,++j)
h += ((unsigned)cv[i]) << ((j&0x3)*8);
return h & p->mask;
}
// Given an id find the value.
cmHtValue_t* _cmHtIdToValue( cmHt_t* p, unsigned id )
{
if( id == cmInvalidId )
return NULL;
unsigned bi = _cmHtBucketIndex(p,id);
assert(bi < p->bucketCnt);
cmHtValue_t* v = p->b[bi].list;
for(; v!=NULL; v=v->link)
if( v->id == id )
return v;
return NULL;
}
// Given a value find the id
cmHtValue_t* _cmHtValueToId( cmHt_t* p, const void* value, unsigned byteCnt, unsigned id )
{
if( id == cmInvalidId )
id = _cmHtGenId(p,value,byteCnt);
unsigned bi = _cmHtBucketIndex(p,id);
assert(bi < p->bucketCnt);
cmHtValue_t* v = p->b[bi].list;
for(; v!=NULL; v=v->link)
if( v->byteCnt==byteCnt && memcmp(value,v->value,byteCnt)==0 )
return v;
return NULL;
}
cmHtRC_t _cmHtDestroy( cmHt_t* p )
{
cmHtRC_t rc = kOkHtRC;
cmLHeapDestroy(&p->lhH);
cmMemFree(p->b);
cmMemFree(p);
return rc;
}
cmHtRC_t cmHashTblCreate( cmCtx_t* ctx, cmHashTblH_t* hp, unsigned bucketCnt )
{
cmHtRC_t rc;
if((rc = cmHashTblDestroy(hp)) != kOkHtRC )
return rc;
cmHt_t* p = cmMemAllocZ(cmHt_t,1);
cmErrSetup(&p->err,&ctx->rpt,"hash table");
if(cmLHeapIsValid(p->lhH = cmLHeapCreate(8192,ctx)) == false )
{
cmErrMsg(&p->err,kLHeapFailHtRC,"Internal linked heap mgr. create failed.");
goto errLabel;
}
// force the bucket count to be a power of two
p->bucketCnt = cmNextPowerOfTwo(bucketCnt);
p->mask = p->bucketCnt - 1;
// calcluate the hash-id bucket mask
for(p->maskShift=0; (0x80000000 & p->mask) == 0; ++p->maskShift )
p->mask <<= 1;
// calculate the maximum collisions per bucket mask
p->linkCnt = ~p->mask;
// allocate the bucket array
p->b = cmMemAllocZ(cmHtBucket_t,p->bucketCnt);
hp->h = p;
errLabel:
if( rc != kOkHtRC )
_cmHtDestroy(p);
return rc;
}
cmHtRC_t cmHashTblDestroy( cmHashTblH_t* hp )
{
cmHtRC_t rc = kOkHtRC;
if(hp==NULL || cmHashTblIsValid(*hp)==false )
return rc;
cmHt_t* p = _cmHtHandleToPtr(*hp);
if((rc = _cmHtDestroy(p)) != kOkHtRC )
return rc;
hp->h = NULL;
return rc;
}
bool cmHashTblIsValid( cmHashTblH_t h )
{ return h.h!=NULL; }
unsigned cmHashTblStoreBase( cmHashTblH_t h, void* v, unsigned byteCnt, bool staticFl )
{
cmHt_t* p = _cmHtHandleToPtr(h);
cmHtValue_t* vp = NULL;
unsigned id = _cmHtGenId(p, v, byteCnt );
// if the value is already stored then there is nothing else to do
if((vp = _cmHtValueToId(p,v,byteCnt,id)) != NULL )
return vp->id;
unsigned bi = _cmHtBucketIndex(p,id);
assert(bi < p->bucketCnt );
cmHtBucket_t* b = p->b + bi;
if( b->avail != NULL )
{
vp = b->avail;
b->avail = b->avail->link;
}
else
{
if( b->nextIdx == p->linkCnt || (id + b->nextIdx) == cmInvalidId )
{
cmErrMsg(&p->err,kHashFaultHtRC,"The hash table bucket at index %i is exhaused.",bi);
return cmInvalidId;
}
vp = cmLhAllocZ(p->lhH,cmHtValue_t,1);
vp->id = id + b->nextIdx++;
}
assert( vp->id != cmInvalidId );
vp->link = b->list;
b->list = vp;
vp->byteCnt = byteCnt;
if( staticFl )
vp->value = v;
else
{
vp->value = cmLhAlloc(p->lhH,char,byteCnt);
memcpy(vp->value,v,byteCnt);
vp->flags = cmSetFlag(vp->flags,kFreeHtFl);
}
return vp->id;
}
unsigned cmHashTblStore( cmHashTblH_t h, void* v, unsigned byteCnt )
{ return cmHashTblStoreBase(h,v,byteCnt,false); }
unsigned cmHashTblStoreStatic( cmHashTblH_t h, void* v, unsigned byteCnt )
{ return cmHashTblStoreBase(h,v,byteCnt,true); }
unsigned _cmHashTblStoreStr( cmHashTblH_t h, const cmChar_t* s, bool staticFl )
{
unsigned n = cmTextLength(s);
if( n == 0 )
{
s = "";
n = 1;
}
return cmHashTblStoreBase(h,(void*)s,n+1,staticFl);
}
unsigned cmHashTblStoreStr( cmHashTblH_t h, const cmChar_t* s )
{ return _cmHashTblStoreStr(h,s,false); }
unsigned cmhashTblStoreStaticStr( cmHashTblH_t h, const cmChar_t* s )
{ return _cmHashTblStoreStr(h,s,true); }
unsigned cmHashTblStoreV( cmHashTblH_t h, const cmChar_t* fmt, va_list vl )
{
cmChar_t* s = NULL;
s = cmTsVPrintfP(s,fmt,vl);
unsigned id = _cmHashTblStoreStr(h,s,false);
cmMemFree(s);
return id;
}
unsigned cmHashTblStoreF( cmHashTblH_t h, const cmChar_t* fmt, ... )
{
va_list vl;
va_start(vl,fmt);
unsigned id = cmHashTblStoreV(h,fmt,vl);
va_end(vl);
return id;
}
unsigned cmHashTblId( cmHashTblH_t h, const void* value, unsigned byteCnt )
{
cmHt_t* p = _cmHtHandleToPtr(h);
cmHtValue_t* vp;
if((vp = _cmHtValueToId(p,value,byteCnt,cmInvalidId)) == NULL )
return cmInvalidId;
return vp->id;
}
unsigned cmHashTblStrToId( cmHashTblH_t h, const cmChar_t* str )
{
if( str == NULL )
return cmInvalidId;
return cmHashTblId(h,str,cmTextLength(str)+1);
}
const void* cmHashTblValue( cmHashTblH_t h, unsigned id, unsigned* byteCntRef )
{
cmHt_t* p = _cmHtHandleToPtr(h);
cmHtValue_t* vp;
if((vp = _cmHtIdToValue(p, id)) != NULL )
{
if( byteCntRef != NULL )
*byteCntRef = vp->byteCnt;
return vp->value;
}
return NULL;
}
const cmChar_t* cmHashTblStr( cmHashTblH_t h, unsigned id )
{ return (const cmChar_t*)cmHashTblValue(h,id,NULL); }
cmHtRC_t cmHashTblRemove( cmHashTblH_t h, unsigned id )
{
cmHt_t* p = _cmHtHandleToPtr(h);
unsigned bi = _cmHtBucketIndex(p,id);
assert(bi < p->bucketCnt);
cmHtBucket_t* b = p->b + bi;
cmHtValue_t* vp = b->list;
cmHtValue_t* pp = NULL;
for(; vp!=NULL; vp=vp->link)
{
if( vp->id == id )
{
if( pp == NULL )
b->list = vp->link;
else
pp->link = vp->link;
break;
}
pp = vp;
}
if( vp == NULL )
return cmErrMsg(&p->err,kInvalidIdHtRC,"A value could not be found for the hash id 0x%x.",id);
if( cmIsFlag(vp->flags,kFreeHtFl ) )
cmLhFree(p->lhH,vp->value);
vp->flags = 0;
vp->value = NULL;
vp->byteCnt = 0;
// Note: Do not set the id to zero since we want to consert id's
// and this recd will be reused by the next call to cmHashTblStoreBase().
return kOkHtRC;
}
cmHtRC_t cmHashTblLastRC( cmHashTblH_t h )
{
cmHt_t* p = _cmHtHandleToPtr(h);
return cmErrLastRC(&p->err);
}
void _cmHashTblBucketReport( cmHtBucket_t* b, cmRpt_t* rpt )
{
cmHtValue_t* vp = b->list;
unsigned i;
for(i=0; vp!=NULL && i<10; vp=vp->link,++i)
cmRptPrintf(rpt,"0x%x : %s\n",vp->id,((const cmChar_t*)vp->value));
cmRptPrintf(rpt,"\n");
}
void cmHashTblReport( cmHashTblH_t h, cmRpt_t* rpt )
{
cmHt_t* p = _cmHtHandleToPtr(h);
unsigned i;
for(i=0; i<p->bucketCnt; ++i)
{
//if( p->b[i].nextIdx > 0 )
// cmRptPrintf(rpt,"%i,%i\n",i,p->b[i].nextIdx);
if( p->b[i].nextIdx > 100 )
_cmHashTblBucketReport(p->b + i,rpt);
}
}
cmHtRC_t cmHashTblTest( cmCtx_t* ctx )
{
cmHtRC_t rc = kOkHtRC;
cmHashTblH_t h = cmHashTblNullHandle;
cmErr_t err;
cmErrSetup(&err,&ctx->rpt,"hash table test");
if((rc = cmHashTblCreate(ctx,&h,8192)) != kOkHtRC )
return cmErrMsg(&err,rc,"Hash table create failed.");
const cmChar_t* arr[] =
{
"1",
"12",
"123",
"1234",
"12345",
"123456",
"123456",
"123456",
NULL
};
unsigned n = sizeof(arr)/sizeof(arr[0]);
unsigned ids[ n ];
int i = 0;
// store the values from arr[]
for(; arr[i]!=NULL; ++i)
if((ids[i] = cmHashTblStoreStr(h,arr[i])) == cmInvalidId )
{
rc = cmErrMsg(&err,cmHashTblLastRC(h),"Hash store failed on: '%s.",cmStringNullGuard(arr[i]));
goto errLabel;
}
/*
// remove a value
unsigned rem_idx = 3;
if((rc = cmHashTblRemove(h, ids[rem_idx] )) != kOkHtRC )
{
rc = cmErrMsg(&err,rc,"Hash removed failed.");
goto errLabel;
}
// insert the same value - which should restore the removed value
if((ids[rem_idx] = cmHashTblStoreStr(h,arr[rem_idx])) == cmInvalidId )
{
rc = cmErrMsg(&err,cmHashTblLastRC(h),"Hash store failed on: '%s.",cmStringNullGuard(arr[rem_idx]));
goto errLabel;
}
*/
// lookup all the stored values by id
for(--i; i>=0; --i)
{
const cmChar_t* s;
if((s = cmHashTblStr(h,ids[i])) == NULL )
rc = cmErrMsg(&err,kInvalidIdHtRC,"The value associated with hash-id:0x%x could not be found.",ids[i]);
else
printf("%i : %s\n",i,cmStringNullGuard(s));
}
for(i=0; arr[i]!=NULL; ++i)
{
unsigned id = cmHashTblStrToId(h, arr[i]);
printf("%i : 0x%x : %s\n",i, id, cmStringNullGuard(cmHashTblStr(h, id)));
}
cmHashTblReport(h, &ctx->rpt );
errLabel:
cmHashTblDestroy(&h);
return rc;
}

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#ifndef cmHashTbl_h
#define cmHashTbl_h
#ifdef __cplusplus
extern "C" {
#endif
enum
{
kOkHtRC,
kLHeapFailHtRC,
kHashFaultHtRC,
kInvalidIdHtRC
};
typedef cmRC_t cmHtRC_t;
typedef cmHandle_t cmHashTblH_t;
extern cmHashTblH_t cmHashTblNullHandle;
cmHtRC_t cmHashTblCreate( cmCtx_t* ctx, cmHashTblH_t* hp, unsigned bucketCnt );
cmHtRC_t cmHashTblDestroy( cmHashTblH_t* hp );
bool cmHashTblIsValid( cmHashTblH_t h );
// cmhashTblStoreBase() is the canonical store function.
// Set 'staticFl' to true if the value does not need to be reallocated
// and copied into the internal storage space.
// Returns a value which uniquely identifies the value. If a unique
// identifier cannot be generated then the function returns cmInvalidId
// and sets the hash table error code to kHashFaultRC.
unsigned cmHashTblStoreBase( cmHashTblH_t h, void* v, unsigned byteCnt, bool staticFl );
unsigned cmHashTblStore( cmHashTblH_t h, void* v, unsigned byteCnt );
unsigned cmHashTblStoreStatic( cmHashTblH_t h, void* v, unsigned byteCnt );
unsigned cmHashTblStoreStr( cmHashTblH_t h, const cmChar_t* s );
unsigned cmhashTblStoreStaticStr( cmHashTblH_t h, const cmChar_t* s );
unsigned cmHashTblStoreV( cmHashTblH_t h, const cmChar_t* fmt, va_list vl );
unsigned cmHashTblStoreF( cmHashTblH_t h, const cmChar_t* fmt, ... );
// Given a value find an id.
unsigned cmHashTblId( cmHashTblH_t h, const void* value, unsigned byteCnt );
unsigned cmHashTblStrToId( cmHashTblH_t h, const cmChar_t* str );
// Returns NULL if no value is associated with 'id'.
// 'byteCntRef' is optional.
const void* cmHashTblValue( cmHashTblH_t h, unsigned id, unsigned* byteCntRef );
// Wrapper around cmHashTblValue() which assumes that the stored value is a
// zero terminated string.
const cmChar_t* cmHashTblStr( cmHashTblH_t h, unsigned id );
// Remove a value.
cmHtRC_t cmHashTblRemove( cmHashTblH_t h, unsigned id );
// Return the last error id generated by the cmHashTbl object.
cmHtRC_t cmHashTblLastRC( cmHashTblH_t h );
void cmHashTblReport( cmHashTblH_t h, cmRpt_t* rpt );
cmHtRC_t cmHashTblTest( cmCtx_t* ctx );
#ifdef __cplusplus
}
#endif
#endif