Category : C Source Code
Archive   : TC_CODE.ZIP
Filename : SPACE

in space
/* - always returns 0
/*
sprt int s(0),p [
pl"loc ptr len key;pl"
while(p=s(p)) [
pn p;pn s(p);pn s(p+1);pn s(p+2);pl"
]]
/*
/* get a block of cells from the free-cell chain of space
/* - return index of head of block
/* - return 0 if block of cells not available
/*
sget int s(0),l [
int pp,p,sp
sp=s(0)
while((p=sp)!=0) [
sp=s(p)
if(s(p+1)>=l+4) [
s(p+l)=sp
s(pp)=p+l
s(p+l+1)=s(p+1)-l
return p
]
else if (s(p+1)>=l) [
s(pp)=sp
return p
]
pp=p
]]
/*
/* append the block of cells at

to the free-cell chain of space
/* - always returns 0
/*
sfree int s(0),p,l [
int pp,sp




sp=s(0)
while((sp!=0)*(sp pp=sp;sp=s(sp)
]
s(pp)=p;s(p)=sp;s(p+1)=l
if((pp!=0)*(pp+s(pp+1)==p) [
s(p=pp)=sp;l=s(p+1)=l+s(p+1)
]
if((sp!=0)*(sp==p+l)) [
s(p)=s(sp);s(p+1)=s(p+1)+s(sp+1)
]]
/*
/* change the size of the block of cells at

in space from to
/* - return the index of the new block
/* - preserve the contents of the old block
/* - if new block smaller than old, return excess to free-cell chain
/* - return 0 if space unavailable for new block
/*
sgrow int s(0),p,l0,l1 [
int p1
if(l0>l1+2) [p1=p;sfree(s,p+l1,l0-l1)]
if(l0 if((p1=sget(s,l1))==0) return
scopy(s,p,l0,p1)
sfree(s,p,l0)
]
s(p1+1)=l1
return p1
]
/*
/* copy the cells at in space to
/* - always returns 0
/*
scopy int s(0),p0,l0,p1 [
int i
while(i s(p1+i)=s(p0+i)
i=i+1
]]
/*
/* modify the block with key on chain

in space to be of size
/* - return index of (the data part of) the block
/* - if is non-positive, delete the block & return 0
/* - if a block with key doesn't exist, allocate it
/* - if is positive & return is 0, space wasn't available
/*
sblock int s(0),p,key,l [
int pp
if(l<=0) return sdelete(s,p,key)
while(p=s(pp=p)) [
if(s(p+2)==key) [
if((p=sgrow(s,p,s(p+1),l+3))==0) return
s(pp)=p
return p+3
]
]
if((p=sget(s,l+3))==0) return
s(pp)=p;s(p)=0;s(p+1)=l+3;s(p+2)=key
return p+3
]
/*
/* locate the block with key on chain

of space




/* - return index of (the data part of) the block
/* - return 0 if block with key not found
/*
sloc int s(0),p,key [
while(p=s(p))
if(s(p+2)==key) return p+3
]
/*
/* delete the block with key from chain

in space
/* - always returns 0
/*
sdelete int s(0),p,key [
int pp
while(p=s(pp=p)) [
if(s(p+2)==key) [
s(pp)=s(p)
return sfree(s,p,s(p+1))
]
]]
(elete int s(0),p,key [
int pp
while(p=s(pp=p)) [
if(s(p+2)==key) [