*** empty log message ***

tecs/buf.c

@@ -0,0 +1,162 @@
+#include <math.h>
+#include <string.h>
+#include <strings.h>
+#include <stdlib.h>
+#include "buf.h"
+
+#define TWO28 268435456.0
+#define MAXINT 2147483647
+
+/* static char *null="\0"; */
+
+int buf_get_int(buf_type *buf)
+{ char *b;
+  int *res;
+
+  b=buf->buf;
+  if (b==NULL) return(0);
+  if (b[0]!=1 || buf->size<5) {buf->buf=NULL; return(0); }
+  b++;
+  res=(int *)b;
+  b+=4;
+  buf->size-=5;
+  buf->buf=b;
+  return(*res);
+}
+
+char *buf_get_str(buf_type *buf)
+{ char *b;
+  int l;
+
+  b=buf->buf;
+  if (b==NULL) return("");
+  if (b[0]==1 || b[0]==2) return("");
+  l=strlen(b);
+  if (buf->size<=l) {buf->buf=NULL; return(""); }
+  buf->buf+=l+1;
+  buf->size-=l+1;
+  return(b);
+}
+
+float buf_get_float(buf_type *buf)
+{ char *b;
+  float res;
+  int *mant, iexp;
+
+  b=buf->buf;
+  if (b==NULL) return(0.0);
+  if (b[0]!=2 || buf->size<6) { buf->buf=NULL; return(0.0); }
+  iexp=b[1];
+  b+=2;
+  mant=(int *)b;
+  b+=4;
+  buf->size-=6;
+  res=(float)ldexp(*mant/TWO28, iexp);
+  buf->buf=b;
+  return res;
+}
+
+int buf_size(buf_type *buf)
+{
+  if (buf->buf==NULL) return(-1);
+  return (buf->size);
+}
+
+void buf_put_int(buf_type *buf, int val)
+{ char *b;
+
+  b=buf->buf;
+  if (b==NULL) return;
+  b[0]=1;
+  b++;
+  if (buf->size<=4) {buf->buf=NULL; return; }
+  *(int *)b=val;
+  b+=4;
+  buf->size-=5;
+  buf->buf=b;
+  return;
+}
+
+void buf_put_str(buf_type *buf, char *str)
+{ char *b;
+  int l;
+
+  if (str[0]<=2 && str[0]!='\0') { buf->buf=NULL; return; };
+  b=buf->buf;
+  if (b==NULL) return;
+  l=strlen(str);
+  if (buf->size<=l) { buf->buf=NULL; return; }
+  strcpy(b, str);
+  buf->buf+=l+1;
+  buf->size-=l+1;
+}
+
+int buf_nint(float val)
+{ int res;
+
+  if (val<0) {
+    if (val<-MAXINT) {
+      return(-MAXINT);
+    } else {
+      return(val-0.5);
+    }
+  } else {
+    if (val>MAXINT) {
+      return(MAXINT);
+    } else {
+      return(val+0.5);
+    }
+  }
+}
+  
+void buf_put_float(buf_type *buf, float val)
+{ char *b;
+  double d;
+  int iexp;
+  int mant;
+
+  b=buf->buf;
+  if (b==NULL) return;
+  if (buf->size<=4) {buf->buf=NULL; return; }
+  d=frexp((double)val, &iexp);
+  mant=buf_nint(d*TWO28);
+  if (iexp>127) iexp=127;
+  if (iexp<-128) iexp=-128;
+  b[0]=2;
+  b[1]=iexp;
+  b+=2;
+  *(int *)b=mant;
+  b+=4;
+  buf->size-=6;
+  buf->buf=b;
+}
+
+void buf_put_end(buf_type *buf)
+{ buf->buf=buf->start;
+  buf->usize=buf->isize-buf->size;
+  buf->size=buf->usize;
+}
+
+void buf_put_start(buf_type *buf)
+{ buf->buf=buf->start;
+  buf->size=buf->isize;
+}
+
+void buf_reset(buf_type *buf)
+{ buf->buf=buf->start;
+  buf->size=buf->usize;
+}
+
+buf_type *buf_create(size_t size)
+{ buf_type *buf;
+
+  buf=malloc(sizeof(*buf));
+  buf->start=malloc(size);
+  buf->isize=size;
+  return(buf);
+}
+
+void buf_free(buf_type *buf)
+{ free(buf->buf);
+  free(buf);
+}