C 32 bit hash_file accessible from tcl for faster hash calculatons

src/actions.c

@@ -30,6 +30,35 @@ void here(int i)
   fprintf(stderr, "here %d\n", i);
 }
 
+/* super simple 32 bit hashing function for files
+ * If you want high collision resistance and 
+ * avoid 'birthday problem' collisions use a better hash function, like md5sum
+ * or sha256sum 
+ */
+unsigned int hash_file(const char *f)
+{
+  int fd;
+  int n, i;
+  unsigned int h=5381;
+  unsigned char line[4096];
+  fd = open(f, O_RDONLY);
+  if(fd >= 0) {
+    while( (n = read(fd, line, sizeof(line))) ) {
+      for(i = 0; i < n; i++) {
+        /* skip CRs so hashes will match on unix / windows */
+        if(i < n - 1 && line[i] == '\r' && line[i+1] == '\n') continue;
+        h += (h << 5) + line[i];
+      }
+    }
+    close(fd);
+    return h;
+  } else {
+    fprintf(stderr, "Can not open file %s\n", f);
+  }
+  return 0;
+}
+
+
 void set_modify(int mod)
 {
   char *top_path;

src/editprop.c

@@ -158,7 +158,7 @@ int my_snprintf(char *string, int size, const char *format, ...)
       format_spec = 0;
       prev = f + 1;
     }
-    else if(format_spec && (*f == 'd' || *f == 'x' || *f == 'c') ) {
+    else if(format_spec && (*f == 'd' || *f == 'x' || *f == 'c' || *f == 'u') ) {
       char nfmt[50], nstr[50];
       int i, nlen;
       i = va_arg(args, int);

src/scheduler.c

@@ -1133,7 +1133,19 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
   }
 
   else if(argv[1][0] == 'h') {   
-    if(!strcmp(argv[1],"help"))
+    if(!strcmp(argv[1],"hash_file"))
+    {
+     unsigned int h;
+     char s[40];
+     cmd_found = 1;
+     if(argc > 2) {
+       h = hash_file(argv[2]);
+       my_snprintf(s, S(s), "%u", h);
+       Tcl_SetResult(interp, s, TCL_VOLATILE);
+     }
+    }
+   
+    else if(!strcmp(argv[1],"help"))
     {
      cmd_found = 1;
      xschem_cmd_help(argc, argv);
@@ -1694,7 +1706,6 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
    
     else if(!strcmp(argv[1],"paste"))
     {
-      xRect boundbox;
       cmd_found = 1;
       merge_file(2,".sch");
       if(argc > 3) {

src/xschem.h

@@ -887,6 +887,7 @@ extern void set_grid(double);
 extern void create_plot_cmd(void);
 extern void set_modify(int mod);
 extern void dbg(int level, char *fmt, ...);
+extern unsigned int hash_file(const char *f);
 extern void here(int i);
 extern void print_version(void);
 extern int set_netlist_dir(int force, char *dir);

tests/xschemtest.tcl

@@ -7,6 +7,7 @@
 ## - logic simulation engine
 ## - print png, svg, pdf
 ## - trim wires
+## - copy/paste operations
 ## run:
 # xschem --script /path/to/drawtest.tcl
 ## optionally with logging to catch memory leaks:
@@ -18,20 +19,6 @@
 ## calculate 32 bit hash of file, used to compare files.
 ## This is NOT a crypto hash, and NOT even a strong collision resistant hash
 ## but for our purposes this is enough
-proc hash_file {f} {
-  set hash 5381
-  set fd [open $f r]
-  fconfigure $fd -encoding binary -translation binary
-  set data [read $fd]
-  ## hash should be the same on windows: remove carriage returns
-  regsub -all {\r} $data {} data
-  close $fd
-  for {set i 0} {$i < [string length $data]} {incr i} {
-    set asciicode [scan [string index $data $i] %c]
-    set hash [expr {($hash * 33 + $asciicode) & 0xffffffff}]
-  }
-  return $hash
-}
 
 ## move schematic and redraw in a loop.
 proc drawtest {} {
@@ -160,13 +147,13 @@ proc xschemtest {{view 0}} {
     foreach {f h} {
         greycnt.v              389394682
         mos_power_ampli.spice  1186348644
-        autozero_comp.spice    1416313184
+        autozero_comp.spice    2011673313
         loading.vhdl           3834408538
         LCC_instances.spice    3918341865
         simulate_ff.spice      1321596936
         rom8k.spice            2198713988
     } {
-      if { [hash_file $netlist_dir/$f] == $h } {
+      if { [xschem hash_file $netlist_dir/$f] == $h } {
         puts "$f netlist check OK"
       } else {
         puts "$f netlist check FAIL"