build system revision

[vg.git] / vg_string.c

diff --git a/vg_string.c b/vg_string.c
new file mode 100644 (file)
index 0000000..1a38479
--- /dev/null
+++ b/vg_string.c
@@ -0,0 +1,204 @@
+#include "vg_string.h"
+#include "vg_platform.h"
+#include <string.h>
+
+i32 vg_str_storage( vg_str *str )
+{
+   if( str->len == -1 ){
+      if( str->buffer ){
+         vg_str_dynamic *arr = (vg_str_dynamic *)str->buffer;
+         return (arr-1)->len;
+      }
+      else return 0;
+   }
+   else return str->len;
+}
+
+/*
+ * Reset string. If len is -1 (dynamically allocated), buffer must be either 
+ * NULL or be acquired from malloc or realloc
+ */
+void vg_strnull( vg_str *str, char *buffer, i32 len )
+{
+   str->buffer = buffer;
+   if( buffer )
+      str->buffer[0] = '\0';
+
+   str->i = 0;
+   str->len = len;
+
+   if( len == 0 )
+      vg_fatal_error( "0 length string allocation\n" );
+}
+
+void vg_strfree( vg_str *str )
+{
+   if( str->len == -1 ){
+      if( str->buffer ){
+         vg_str_dynamic *arr = (vg_str_dynamic *)str->buffer;
+         free( arr-1 );
+
+         str->buffer = NULL;
+         str->i = 0;
+      }
+   }
+}
+
+/*
+ * Double the size of the dynamically allocated string. If unallocated, alloc of
+ * 16 bytes minimum.
+ */
+static i32 vg_str_dynamic_grow( vg_str *str )
+{
+   if( str->buffer ){
+      vg_str_dynamic *hdr = ((vg_str_dynamic *)str->buffer) - 1;
+      i32 total = (hdr->len + sizeof(vg_str_dynamic)) * 2;
+      hdr = realloc( hdr, total );
+      hdr->len = total - sizeof(vg_str_dynamic);
+      str->buffer = (char *)(hdr+1);
+      return hdr->len;
+   }
+   else {
+      vg_str_dynamic *hdr = malloc(16);
+      hdr->len = 16-sizeof(vg_str_dynamic);
+      str->buffer = (char *)(hdr+1);
+      str->buffer[0] = '\0';
+      return hdr->len;
+   }
+}
+
+void vg_strcat( vg_str *str, const char *append )
+{
+   if( !append || (str->i == -1) ) return;
+
+   i32 max = vg_str_storage( str ),
+       i   = 0;
+
+append:
+   if( str->i == max ){
+      if( str->len == -1 )
+         max = vg_str_dynamic_grow( str );
+      else{
+         str->i = -1;
+         str->buffer[ max-1 ] = '\0';
+         return;
+      }
+   }
+
+   char c = append[ i ++ ];
+   str->buffer[ str->i ] = c;
+
+   if( c == '\0' )
+      return;
+
+   str->i ++;
+   goto append;
+}
+
+void vg_strcatch( vg_str *str, char c )
+{
+   vg_strcat( str, (char[]){ c, '\0' } );
+}
+
+/* 
+ * FIXME: Negative numbers
+ */
+void vg_strcati32( vg_str *str, i32 value )
+{
+   if( value ){
+      char temp[32];
+      int i=0;
+      while( value && (i<31) ){
+         temp[ i ++ ] = '0' + (value % 10);
+         value /= 10;
+      }
+
+      char reverse[32];
+      for( int j=0; j<i; j ++ )
+         reverse[j] = temp[ i-1-j ];
+      reverse[i] = '\0';
+
+      vg_strcat( str, reverse );
+   }
+   else
+      vg_strcat( str, "0" );
+}
+
+void vg_strcati32r( vg_str *str, i32 value, i32 n, char alt )
+{
+   char temp[32];
+   i32 i=0;
+   while( value ){
+      if( i>=n ) 
+         break;
+
+      temp[ n-1 - (i ++) ] = '0' + (value % 10);
+      value /= 10;
+   }
+
+   for( ;i<n; i ++ )
+      temp[ n-1 - i ] = alt;
+
+   temp[n]='\0';
+   vg_strcat( str, temp );
+}
+
+int vg_strgood( vg_str *str )
+{
+   if( str->i == -1 ) return 0;
+   else return 1;
+}
+
+/*
+ * Returns pointer to last instance of character
+ */
+char *vg_strch( vg_str *str, char c )
+{
+   char *ptr = NULL;
+   for( i32 i=0; i<str->i; i++ ){
+      if( str->buffer[i] == c )
+         ptr = str->buffer+i;
+   }
+
+   return ptr;
+}
+
+u32 vg_strncpy( const char *src, char *dst, u32 len,
+                enum strncpy_behaviour behaviour )
+{
+   for( u32 i=0; i<len; i++ ){
+      dst[i] = src[i];
+
+      if( !src[i] ) return i;
+
+      if( i == len-1 ){
+         if( behaviour == k_strncpy_always_add_null ){
+            dst[i] = '\0';
+            return i;
+         }
+         else if( behaviour == k_strncpy_overflow_fatal ){
+            vg_fatal_error( "Strncpy dest exceeded buffer length\n" );
+         }
+      }
+   }
+
+   return 0;
+}
+
+u32 vg_strdjb2( const char *str )
+{
+   u32 hash = 5381, c;
+
+   while( (c = *str++) )
+      hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
+
+   return hash;
+}
+
+int vg_strdjb2_eq( const char *s1, u32 h1, const char *s2, u32 h2 )
+{
+   if( h1 == h2 ){
+      if(!strcmp(s1, s2)) return 1;
+      else return 0;
+   } else return 0;
+}