1 files changed, 128 insertions, 0 deletions
diff --git a/src/chain.c b/src/chain.c
new file mode 100644
index 00000000..0324687d
--- /dev/null
+++ b/src/chain.c
@@ -0,0 +1,128 @@
+/*
+ * File: chain.c
+ * Concomitant control chain (CCC)
+ * Theory and code by Jorge Arellano Cid
+ *
+ * Copyright 2001, 2002 Jorge Arellano Cid <jcid@dillo.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ */
+
+#include "msg.h"
+#include "chain.h"
+#include "../dlib/dlib.h"
+
+#define VERBOSE 0
+
+/*
+ * Create and initialize a new chain-link
+ */
+ChainLink *a_Chain_new(void)
+{
+   return dNew0(ChainLink, 1);
+}
+
+/*
+ * Create a new link from module A to module B.
+ * 'Direction' tells whether to make a forward or backward link.
+ * => The link from 'A' to 'B' has 'Direction' direction.
+ * => The main flow of information names the FWD direction.
+ * => AtoB_branch: branch on which 'B' receives communications from 'A'
+ * => BtoA_branch: branch on which 'A' receives communications from 'B'
+ */
+ChainLink *a_Chain_link_new(ChainLink *AInfo, ChainFunction_t AFunc,
+                            int Direction, ChainFunction_t BFunc,
+                            int AtoB_branch, int BtoA_branch)
+{
+   ChainLink *NewLink = a_Chain_new();
+   ChainLink *OldLink = AInfo;
+
+   if (Direction == BCK) {
+      NewLink->Fcb       = AFunc;
+      NewLink->FcbInfo   = AInfo;
+      NewLink->FcbBranch = BtoA_branch;
+      OldLink->Bcb       = BFunc;
+      OldLink->BcbInfo   = NewLink;
+      OldLink->BcbBranch = AtoB_branch;
+
+   } else { /* FWD */
+      NewLink->Bcb       = AFunc;
+      NewLink->BcbInfo   = AInfo;
+      NewLink->BcbBranch = BtoA_branch;
+      OldLink->Fcb       = BFunc;
+      OldLink->FcbInfo   = NewLink;
+      OldLink->FcbBranch = AtoB_branch;
+   }
+
+   return NewLink;
+}
+
+/*
+ * Unlink a previously used link.
+ * 'Direction' tells whether to unlink the forward or backward link.
+ */
+void a_Chain_unlink(ChainLink *Info, int Direction)
+{
+   if (Direction == FWD) {
+      Info->Fcb = NULL;
+      Info->FcbInfo = NULL;
+      Info->FcbBranch = 0;
+   } else {      /* BCK */
+      Info->Bcb = NULL;
+      Info->BcbInfo = NULL;
+      Info->BcbBranch = 0;
+   }
+}
+
+/*
+ * Issue the forward callback of the 'Info' link
+ */
+int a_Chain_fcb(int Op, ChainLink *Info, void *Data1, void *Data2)
+{
+   if (Info->Fcb) {
+      Info->Fcb(Op, Info->FcbBranch, FWD, Info->FcbInfo, Data1, Data2);
+      return 1;
+   }
+   return 0;
+}
+
+/*
+ * Issue the backward callback of the 'Info' link
+ */
+int a_Chain_bcb(int Op, ChainLink *Info, void *Data1, void *Data2)
+{
+   if (Info->Bcb) {
+      Info->Bcb(Op, Info->BcbBranch, BCK, Info->BcbInfo, Data1, Data2);
+      return 1;
+   }
+   return 0;
+}
+
+
+/*
+ * Allocate and initialize a new DataBuf structure
+ */
+DataBuf *a_Chain_dbuf_new(void *buf, int size, int code)
+{
+   DataBuf *dbuf = dNew(DataBuf, 1);
+   dbuf->Buf = buf;
+   dbuf->Size = size;
+   dbuf->Code = code;
+   return dbuf;
+}
+
+/*
+ * Show some debugging info
+ */
+void a_Chain_debug_msg(char *FuncStr, int Op, int Branch, int Dir)
+{
+#if VERBOSE
+   const char *StrOps[] = {"", "OpStart", "OpSend",
+                            "OpStop", "OpEnd", "OpAbort"};
+   MSG("%-*s: %-*s [%d%s]\n",
+       12, FuncStr, 7, StrOps[Op], Branch, (Dir == 1) ? "F" : "B");
+#endif
+}