1 files changed, 100 insertions, 0 deletions

diff --git a/src/p_checksum.c b/src/p_checksum.c
new file mode 100644
index 0000000..5fb6101
--- /dev/null
+++ b/src/p_checksum.c
@@ -0,0 +1,100 @@
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <stdlib.h> /* exit(), atexit() */
+
+#include "p_checksum.h"
+#include "md5.h"
+#include "doomstat.h" /* players{,ingame} */
+#include "lprintf.h"
+
+/* forward decls */
+static void p_checksum_cleanup(void);
+void checksum_gamestate(int tic);
+
+/* vars */
+static void p_checksum_nop(int tic){} /* do nothing */
+void (*P_Checksum)(int) = p_checksum_nop;
+
+/*
+ * P_RecordChecksum
+ * sets up the file and function pointers to write out checksum data
+ */
+static FILE *outfile = NULL;
+static struct MD5Context md5global;
+
+void P_RecordChecksum(const char *file) {
+    size_t fnsize;
+
+    fnsize = strlen(file);
+
+    /* special case: write to stdout */
+    if(0 == strncmp("-",file,MIN(1,fnsize)))
+        outfile = stdout;
+    else {
+        outfile = fopen(file,"wb");
+        if(NULL == outfile) {
+            I_Error("cannot open %s for writing checksum:\n%s\n",
+                    file, strerror(errno));
+        }
+        atexit(p_checksum_cleanup);
+    }
+
+    MD5Init(&md5global);
+
+    P_Checksum = checksum_gamestate;
+}
+
+void P_ChecksumFinal(void) {
+    int i;
+    unsigned char digest[16];
+
+    if (!outfile)
+      return;
+
+    MD5Final(digest, &md5global);
+    fprintf(outfile, "final: ");
+    for (i=0; i<16; i++)
+        fprintf(outfile,"%x", digest[i]);
+    fprintf(outfile, "\n");
+    MD5Init(&md5global);
+}
+
+static void p_checksum_cleanup(void) {
+    if (outfile && (outfile != stdout))
+        fclose(outfile);
+}
+
+/*
+ * runs on each tic when recording checksums
+ */
+void checksum_gamestate(int tic) {
+    int i;
+    struct MD5Context md5ctx;
+    unsigned char digest[16];
+    char buffer[2048];
+
+    fprintf(outfile,"%6d, ", tic);
+
+    /* based on "ArchivePlayers" */
+    MD5Init(&md5ctx);
+    for (i=0 ; i<MAXPLAYERS ; i++) {
+        if (!playeringame[i]) continue;
+
+#ifdef HAVE_SNPRINTF
+        snprintf (buffer, sizeof(buffer), "%d", players[i].health);
+#else
+        sprintf (buffer, "%d", players[i].health);
+#endif
+        buffer[sizeof(buffer)-1] = 0;
+
+        MD5Update(&md5ctx, (md5byte const *)&buffer, strlen(buffer));
+    }
+    MD5Final(digest, &md5ctx);
+    for (i=0; i<16; i++) {
+        MD5Update(&md5global, (md5byte const *)&digest[i], sizeof(digest[i]));
+        fprintf(outfile,"%x", digest[i]);
+    }
+
+    fprintf(outfile,"\n");
+}