serval-dna/overlay_buffer.c
gardners 2ff8541049 Woot! overlay mode now emits regular tick frames on interfaces it knows about.
Still doesn't know about broadcast properly or a pile of other things, oh, and
the frames are completely empty, but none the less, we are now sending frames.
2011-08-09 12:45:24 +08:00

102 lines
2.3 KiB
C

#include "mphlr.h"
overlay_buffer *ob_new(int size)
{
overlay_buffer *ret=calloc(sizeof(overlay_buffer),1);
if (!ret) return NULL;
ob_unlimitsize(ret);
return ret;
}
int ob_free(overlay_buffer *b)
{
if (!b) return WHY("Asked to free NULL");
if (b->bytes) free(b->bytes);
b->bytes=NULL;
b->allocSize=0;
b->sizeLimit=0;
free(b);
return 0;
}
int ob_checkpoint(overlay_buffer *b)
{
if (!b) return WHY("Asked to checkpoint NULL");
b->checkpointLength=b->length;
return 0;
}
int ob_rewind(overlay_buffer *b)
{
if (!b) return WHY("Asked to rewind NULL");
b->length=b->checkpointLength;
return 0;
}
int ob_limitsize(overlay_buffer *b,int bytes)
{
if (!b) return WHY("Asked to limit size of NULL");
if (b->length>bytes) return WHY("Length of data in buffer already exceeds size limit");
if (b->checkpointLength>bytes) return WHY("Checkpointed length of data in buffer already exceeds size limit");
if (bytes<0) return WHY("Cant limit buffer to a negative size");
b->sizeLimit=bytes;
return 0;
}
int ob_unlimitsize(overlay_buffer *b)
{
if (!b) return WHY("b is NULL");
b->sizeLimit=-1;
return 0;
}
int ob_makespace(overlay_buffer *b,int bytes)
{
if (b->sizeLimit!=-1) {
if (b->length+bytes>b->sizeLimit) return WHY("Asked to make space beyond size limit");
}
if (b->length+bytes>=b->allocSize)
{
int newSize=b->length+bytes;
if (newSize<64) newSize=64;
if (newSize&63) newSize+=64-(newSize&63);
if (newSize>1024) {
if (newSize&1023) newSize+=1024-(newSize&1023);
}
if (newSize>65536) {
if (newSize&65535) newSize+=65536-(newSize&65535);
}
unsigned char *r=realloc(b->bytes,newSize);
if (!r) return WHY("realloc() failed");
b->bytes=r;
b->allocSize=newSize;
return 0;
}
else
return 0;
}
int ob_append_bytes(overlay_buffer *b,unsigned char *bytes,int count)
{
if (ob_makespace(b,count)) return WHY("ob_makespace() failed");
bcopy(bytes,&b->bytes[b->length],count);
b->length+=count;
return 0;
}
int ob_append_short(overlay_buffer *b,unsigned short v)
{
unsigned short s=htons(v);
return ob_append_bytes(b,(unsigned char *)&s,sizeof(unsigned short));
}
int ob_append_int(overlay_buffer *b,unsigned int v)
{
unsigned int s=htonl(v);
return ob_append_bytes(b,(unsigned char *)&s,sizeof(unsigned int));
}