Replace PuTTY's 2-3-4 tree implementation with the shiny new counted

one, in preparation for using it to speed up scrollback.

[originally from svn r1053]

pageant.c

@@ -224,11 +224,11 @@ static int CALLBACK PassphraseProc(HWND hwnd, UINT msg,
 static void keylist_update(void) {
     struct RSAKey *rkey;
     struct ssh2_userkey *skey;
-    enum234 e;
+    int i;
 
     if (keylist) {
         SendDlgItemMessage(keylist, 100, LB_RESETCONTENT, 0, 0);
-        for (rkey = first234(rsakeys, &e); rkey; rkey = next234(&e)) {
+        for (i = 0; NULL != (rkey = index234(rsakeys, i)); i++) {
             char listentry[512], *p;
             /*
              * Replace two spaces in the fingerprint with tabs, for
@@ -242,7 +242,7 @@ static void keylist_update(void) {
             SendDlgItemMessage (keylist, 100, LB_ADDSTRING,
                                 0, (LPARAM)listentry);
         }
-        for (skey = first234(ssh2keys, &e); skey; skey = next234(&e)) {
+        for (i = 0; NULL != (skey = index234(ssh2keys, i)); i++) {
             char listentry[512], *p;
 	    int len;
             /*
@@ -438,15 +438,15 @@ static void answer_msg(void *msg) {
          * Reply with SSH1_AGENT_RSA_IDENTITIES_ANSWER.
          */
         {
-            enum234 e;
             struct RSAKey *key;
             int len, nkeys;
+	    int i;
 
             /*
              * Count up the number and length of keys we hold.
              */
             len = nkeys = 0;
-            for (key = first234(rsakeys, &e); key; key = next234(&e)) {
+            for (i = 0; NULL != (key = index234(rsakeys, i)); i++) {
                 nkeys++;
                 len += 4;              /* length field */
                 len += ssh1_bignum_length(key->exponent);
@@ -465,7 +465,7 @@ static void answer_msg(void *msg) {
             ret[4] = SSH1_AGENT_RSA_IDENTITIES_ANSWER;
             PUT_32BIT(ret+5, nkeys);
             p = ret + 5 + 4;
-            for (key = first234(rsakeys, &e); key; key = next234(&e)) {
+            for (i = 0; NULL != (key = index234(rsakeys, i)); i++) {
                 PUT_32BIT(p, bignum_bitcount(key->modulus));
                 p += 4;
                 p += ssh1_write_bignum(p, key->exponent);
@@ -481,17 +481,17 @@ static void answer_msg(void *msg) {
          * Reply with SSH2_AGENT_IDENTITIES_ANSWER.
          */
         {
-            enum234 e;
             struct ssh2_userkey *key;
             int len, nkeys;
 	    unsigned char *blob;
 	    int bloblen;
+	    int i;
 
             /*
              * Count up the number and length of keys we hold.
              */
             len = nkeys = 0;
-            for (key = first234(ssh2keys, &e); key; key = next234(&e)) {
+            for (i = 0; NULL != (key = index234(ssh2keys, i)); i++) {
                 nkeys++;
                 len += 4;              /* length field */
 		blob = key->alg->public_blob(key->data, &bloblen);
@@ -511,7 +511,7 @@ static void answer_msg(void *msg) {
             ret[4] = SSH2_AGENT_IDENTITIES_ANSWER;
             PUT_32BIT(ret+5, nkeys);
             p = ret + 5 + 4;
-            for (key = first234(ssh2keys, &e); key; key = next234(&e)) {
+            for (i = 0; NULL != (key = index234(ssh2keys, i)); i++) {
 		blob = key->alg->public_blob(key->data, &bloblen);
                 PUT_32BIT(p, bloblen);
                 p += 4;
@@ -743,9 +743,8 @@ static void answer_msg(void *msg) {
          */
         {
 	    struct RSAKey *rkey;
-	    enum234 e;
 
-            while ( (rkey = first234(rsakeys, &e)) != NULL ) {
+            while ( (rkey = index234(rsakeys, 0)) != NULL ) {
                 del234(rsakeys, rkey);
 		freersakey(rkey);
 		sfree(rkey);
@@ -762,9 +761,8 @@ static void answer_msg(void *msg) {
          */
         {
             struct ssh2_userkey *skey;
-	    enum234 e;
 
-            while ( (skey = first234(ssh2keys, &e)) != NULL ) {
+            while ( (skey = index234(ssh2keys, 0)) != NULL ) {
                 del234(ssh2keys, skey);
 		skey->alg->freekey(skey->data);
 		sfree(skey);
@@ -925,7 +923,6 @@ static void prompt_add_keyfile(void) {
  */
 static int CALLBACK KeyListProc(HWND hwnd, UINT msg,
                                 WPARAM wParam, LPARAM lParam) {
-    enum234 e;
     struct RSAKey *rkey;
     struct ssh2_userkey *skey;
 
@@ -970,11 +967,12 @@ static int CALLBACK KeyListProc(HWND hwnd, UINT msg,
 	    if (HIWORD(wParam) == BN_CLICKED ||
 		HIWORD(wParam) == BN_DOUBLECLICKED) {
 		int n = SendDlgItemMessage (hwnd, 100, LB_GETCURSEL, 0, 0);
+		int i;
 		if (n == LB_ERR) {
 		    MessageBeep(0);
 		    break;
 		}
-                for (rkey = first234(rsakeys, &e); rkey; rkey = next234(&e))
+                for (i = 0; NULL != (rkey = index234(rsakeys, i)); i++)
                     if (n-- == 0)
                         break;
 		if (rkey) {
@@ -982,7 +980,7 @@ static int CALLBACK KeyListProc(HWND hwnd, UINT msg,
 		    freersakey(rkey);
 		    sfree(rkey);
 		} else {
-		    for (skey = first234(ssh2keys, &e); skey; skey = next234(&e))
+		    for (i = 0; NULL != (skey = index234(ssh2keys, i)); i++)
 			if (n-- == 0)
 			    break;
 		    if (skey) {

plink.c

@@ -568,11 +568,10 @@ int main(int argc, char **argv) {
         n = WaitForMultipleObjects(2, handles, FALSE, INFINITE);
         if (n == 0) {
             WSANETWORKEVENTS things;
-	    enum234 e;
 	    SOCKET socket;
-	    extern SOCKET first_socket(enum234 *), next_socket(enum234 *);
+	    extern SOCKET first_socket(int *), next_socket(int *);
 	    extern int select_result(WPARAM, LPARAM);
-            int i;
+            int i, socketstate;
 
             /*
              * We must not call select_result() for any socket
@@ -582,8 +581,8 @@ int main(int argc, char **argv) {
              */
             /* Count the active sockets. */
             i = 0;
-            for (socket = first_socket(&e); socket != INVALID_SOCKET;
+            for (socket = first_socket(&socketstate); socket != INVALID_SOCKET;
-		 socket = next_socket(&e))
+		 socket = next_socket(&socketstate))
                 i++;
 
             /* Expand the buffer if necessary. */
@@ -594,8 +593,8 @@ int main(int argc, char **argv) {
 
             /* Retrieve the sockets into sklist. */
             skcount = 0;
-	    for (socket = first_socket(&e); socket != INVALID_SOCKET;
+	    for (socket = first_socket(&socketstate); socket != INVALID_SOCKET;
-		 socket = next_socket(&e)) {
+		 socket = next_socket(&socketstate)) {
                 sklist[skcount++] = socket;
             }
 

ssh.c

@@ -365,6 +365,42 @@ static int ssh_channelfind(void *av, void *bv) {
     return 0;
 }
 
+static int alloc_channel_id(void) {
+    const int CHANNEL_NUMBER_OFFSET = 256;
+    int low, high, mid;
+    int tsize;
+    struct ssh_channel *c;
+
+    /*
+     * First-fit allocation of channel numbers: always pick the
+     * lowest unused one. To do this, binary-search using the
+     * counted B-tree to find the largest channel ID which is in a
+     * contiguous sequence from the beginning. (Precisely
+     * everything in that sequence must have ID equal to its tree
+     * index plus CHANNEL_NUMBER_OFFSET.)
+     */
+    tsize = count234(ssh_channels);
+
+    low = -1; high = tsize;
+    while (high - low > 1) {
+	mid = (high + low) / 2;
+	c = index234(ssh_channels, mid);
+	if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
+	    low = mid;		       /* this one is fine */
+	else
+	    high = mid;		       /* this one is past it */
+    }
+    /*
+     * Now low points to either -1, or the tree index of the
+     * largest ID in the initial sequence.
+     */
+    {
+	unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
+	assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
+    }
+    return low + 1 + CHANNEL_NUMBER_OFFSET;
+}
+
 static void c_write (char *buf, int len) {
     if ((flags & FLAG_STDERR)) {
         int i;
@@ -2234,9 +2270,7 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
             } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
                 /* Remote side is trying to open a channel to talk to our
                  * X-Server. Give them back a local channel number. */
-                unsigned i;
                 struct ssh_channel *c, *d;
-                enum234 e;
 
 		logevent("Received X11 connect request");
 		/* Refuse if X11 forwarding is disabled. */
@@ -2256,13 +2290,8 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
 				  PKT_END);
 		    } else {
 		      logevent("opening X11 forward connection succeeded");
-		      for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) {
-                          if (d->localid > i)
-                              break;     /* found a free number */
-                          i = d->localid + 1;
-		      }
 		      c->remoteid = GET_32BIT(pktin.body);
-		      c->localid = i;
+		      c->localid = alloc_channel_id();
 		      c->closes = 0;
 		      c->type = CHAN_X11;   /* identify channel type */
 		      add234(ssh_channels, c);
@@ -2277,7 +2306,6 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
                  * agent. Give them back a local channel number. */
                 unsigned i;
                 struct ssh_channel *c;
-                enum234 e;
 
 		/* Refuse if agent forwarding is disabled. */
 		if (!ssh_agentfwd_enabled) {
@@ -2285,15 +2313,9 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
 				PKT_INT, GET_32BIT(pktin.body),
 				PKT_END);
 		} else {
-		    i = 1;
-		    for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
-			if (c->localid > i)
-			    break;     /* found a free number */
-			i = c->localid + 1;
-		    }
 		    c = smalloc(sizeof(struct ssh_channel));
 		    c->remoteid = GET_32BIT(pktin.body);
-		    c->localid = i;
+		    c->localid = alloc_channel_id();
 		    c->closes = 0;
 		    c->type = CHAN_AGENT;   /* identify channel type */
 		    c->u.a.lensofar = 0;
@@ -3512,8 +3534,9 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
     /*
      * So now create a channel with a session in it.
      */
+    ssh_channels = newtree234(ssh_channelcmp);
     mainchan = smalloc(sizeof(struct ssh_channel));
-    mainchan->localid = 100;           /* as good as any */
+    mainchan->localid = alloc_channel_id();
     ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
     ssh2_pkt_addstring("session");
     ssh2_pkt_adduint32(mainchan->localid);
@@ -3537,7 +3560,6 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
     mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
     mainchan->v2.outbuffer = NULL;
     mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
-    ssh_channels = newtree234(ssh_channelcmp);
     add234(ssh_channels, mainchan);
     logevent("Opened channel for session");
 
@@ -3816,7 +3838,6 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
 	    } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
                 unsigned i = ssh2_pkt_getuint32();
                 struct ssh_channel *c;
-                enum234 e;
 
                 c = find234(ssh_channels, &i, ssh_channelfind);
                 if (!c)
@@ -3842,8 +3863,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
                 /*
                  * See if that was the last channel left open.
                  */
-                c = first234(ssh_channels, &e);
+                if (count234(ssh_channels) == 0) {
-                if (!c) {
                     logevent("All channels closed. Disconnecting");
                     ssh2_pkt_init(SSH2_MSG_DISCONNECT);
                     ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
@@ -3902,15 +3922,8 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
                 } else {
                     struct ssh_channel *d;
                     unsigned i;
-                    enum234 e;
 
-                    for (i=1, d = first234(ssh_channels, &e); d;
+                    c->localid = alloc_channel_id();
-                         d = next234(&e)) {
-			if (d->localid > i)
-                            break;     /* found a free number */
-			i = d->localid + 1;
-                    }
-                    c->localid = i;
                     c->closes = 0;
                     c->v2.remwindow = ssh2_pkt_getuint32();
                     c->v2.remmaxpkt = ssh2_pkt_getuint32();
@@ -3936,12 +3949,12 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
             try_send = TRUE;
 	}
         if (try_send) {
-            enum234 e;
+            int i;
             struct ssh_channel *c;
             /*
              * Try to send data on all channels if we can.
              */
-            for (c = first234(ssh_channels, &e); c; c = next234(&e))
+            for (i = 0; NULL != (c = index234(ssh_channels, i)); i++)
                 ssh2_try_send(c);
         }
     }

sshzlib.c

@@ -95,12 +95,12 @@ static void lz77_compress(struct LZ77Context *ctx,
 
 #define INVALID -1		       /* invalid hash _and_ invalid offset */
 struct WindowEntry {
-    int next, prev;		       /* array indices within the window */
+    short next, prev;		       /* array indices within the window */
-    int hashval;
+    short hashval;
 };
 
 struct HashEntry {
-    int first;			       /* window index of first in chain */
+    short first;		       /* window index of first in chain */
 };
 
 struct Match {
@@ -393,7 +393,8 @@ static const unsigned char mirrorbytes[256] = {
 };
 
 typedef struct {
-    int code, extrabits, min, max;
+    short code, extrabits;
+    int min, max;
 } coderecord;
 
 static const coderecord lencodes[] = {
@@ -760,7 +761,7 @@ struct zlib_tableentry;
 
 struct zlib_tableentry {
     unsigned char nbits;
-    int code;
+    short code;
     struct zlib_table *nexttable;
 };
 

tree234.h

@@ -1,33 +1,44 @@
 /*
  * tree234.h: header defining functions in tree234.c.
+ * 
+ * This file is copyright 1999-2001 Simon Tatham.
+ * 
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ * 
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL SIMON TATHAM BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
+ * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
  */
 
 #ifndef TREE234_H
 #define TREE234_H
 
 /*
- * These typedefs are notionally opaque outside tree234.c itself.
+ * This typedef is opaque outside tree234.c itself.
  */
-typedef struct node234_Tag node234;
 typedef struct tree234_Tag tree234;
-typedef struct enum234_Tag enum234;
-
-/*
- * enum234 must be declared here because client code needs to be
- * able to create automatic instances of it. This declaration does
- * not constitute licence to use its internals outside tree234.c.
- * The contents of this structure may change without notice. YOU
- * HAVE BEEN WARNED.
- */
-struct enum234_Tag {
-    node234 *node;
-    int posn;
-};
 
 typedef int (*cmpfn234)(void *, void *);
 
 /*
- * Create a 2-3-4 tree.
+ * Create a 2-3-4 tree. If `cmp' is NULL, the tree is unsorted, and
+ * lookups by key will fail: you can only look things up by numeric
+ * index, and you have to use addpos234() and delpos234().
  */
 tree234 *newtree234(cmpfn234 cmp);
 
@@ -37,33 +48,113 @@ tree234 *newtree234(cmpfn234 cmp);
 void freetree234(tree234 *t);
 
 /*
- * Add an element e to a 2-3-4 tree t. Returns e on success, or if
+ * Add an element e to a sorted 2-3-4 tree t. Returns e on success,
- * an existing element compares equal, returns that.
+ * or if an existing element compares equal, returns that.
  */
 void *add234(tree234 *t, void *e);
 
 /*
- * Find an element e in a 2-3-4 tree t. Returns NULL if not found.
+ * Add an element e to an unsorted 2-3-4 tree t. Returns e on
- * e is always passed as the first argument to cmp, so cmp can be
+ * success, NULL on failure. (Failure should only occur if the
- * an asymmetric function if desired. cmp can also be passed as
+ * index is out of range or the tree is sorted.)
- * NULL, in which case the compare function from the tree proper
+ * 
- * will be used.
+ * Index range can be from 0 to the tree's current element count,
+ * inclusive.
  */
+void *addpos234(tree234 *t, void *e, int index);
+
+/*
+ * Look up the element at a given numeric index in a 2-3-4 tree.
+ * Returns NULL if the index is out of range.
+ * 
+ * One obvious use for this function is in iterating over the whole
+ * of a tree (sorted or unsorted):
+ * 
+ *   for (i = 0; (p = index234(tree, i)) != NULL; i++) consume(p);
+ * 
+ * or
+ * 
+ *   int maxcount = count234(tree);
+ *   for (i = 0; i < maxcount; i++) {
+ *       p = index234(tree, i);
+ *       assert(p != NULL);
+ *       consume(p);
+ *   }
+ */
+void *index234(tree234 *t, int index);
+
+/*
+ * Find an element e in a sorted 2-3-4 tree t. Returns NULL if not
+ * found. e is always passed as the first argument to cmp, so cmp
+ * can be an asymmetric function if desired. cmp can also be passed
+ * as NULL, in which case the compare function from the tree proper
+ * will be used.
+ * 
+ * Three of these functions are special cases of findrelpos234. The
+ * non-`pos' variants lack the `index' parameter: if the parameter
+ * is present and non-NULL, it must point to an integer variable
+ * which will be filled with the numeric index of the returned
+ * element.
+ * 
+ * The non-`rel' variants lack the `relation' parameter. This
+ * parameter allows you to specify what relation the element you
+ * provide has to the element you're looking for. This parameter
+ * can be:
+ * 
+ *   REL234_EQ     - find only an element that compares equal to e
+ *   REL234_LT     - find the greatest element that compares < e
+ *   REL234_LE     - find the greatest element that compares <= e
+ *   REL234_GT     - find the smallest element that compares > e
+ *   REL234_GE     - find the smallest element that compares >= e
+ * 
+ * Non-`rel' variants assume REL234_EQ.
+ * 
+ * If `rel' is REL234_GT or REL234_LT, the `e' parameter may be
+ * NULL. In this case, REL234_GT will return the smallest element
+ * in the tree, and REL234_LT will return the greatest. This gives
+ * an alternative means of iterating over a sorted tree, instead of
+ * using index234:
+ * 
+ *   // to loop forwards
+ *   for (p = NULL; (p = findrel234(tree, p, NULL, REL234_GT)) != NULL ;)
+ *       consume(p);
+ * 
+ *   // to loop backwards
+ *   for (p = NULL; (p = findrel234(tree, p, NULL, REL234_LT)) != NULL ;)
+ *       consume(p);
+ */
+enum {
+    REL234_EQ, REL234_LT, REL234_LE, REL234_GT, REL234_GE
+};
 void *find234(tree234 *t, void *e, cmpfn234 cmp);
+void *findrel234(tree234 *t, void *e, cmpfn234 cmp, int relation);
+void *findpos234(tree234 *t, void *e, cmpfn234 cmp, int *index);
+void *findrelpos234(tree234 *t, void *e, cmpfn234 cmp, int relation,
+		    int *index);
 
 /*
  * Delete an element e in a 2-3-4 tree. Does not free the element,
  * merely removes all links to it from the tree nodes.
+ * 
+ * delpos234 deletes the element at a particular tree index: it
+ * works on both sorted and unsorted trees.
+ * 
+ * del234 deletes the element passed to it, so it only works on
+ * sorted trees. (It's equivalent to using findpos234 to determine
+ * the index of an element, and then passing that index to
+ * delpos234.)
+ * 
+ * Both functions return a pointer to the element they delete, for
+ * the user to free or pass on elsewhere or whatever. If the index
+ * is out of range (delpos234) or the element is already not in the
+ * tree (del234) then they return NULL.
  */
-void del234(tree234 *t, void *e);
+void *del234(tree234 *t, void *e);
+void *delpos234(tree234 *t, int index);
 
 /*
- * Iterate over the elements of a tree234, in order.
+ * Return the total element count of a tree234.
- *
- *   enum234 e;
- *   for (p = first234(tree, &e); p; p = next234(&e)) consume(p);
  */
-void *first234(tree234 *t, enum234 *e);
+int count234(tree234 *t);
-void *next234(enum234 *e);
 
 #endif /* TREE234_H */

winnet.c

@@ -747,11 +747,13 @@ static char *sk_tcp_socket_error(Socket sock) {
 /*
  * For Plink: enumerate all sockets currently active.
  */
-SOCKET first_socket(enum234 *e) {
+SOCKET first_socket(int *state) {
-    Actual_Socket s = first234(sktree, e);
+    Actual_Socket s;
+    *state = 0;
+    s = index234(sktree, (*state)++);
     return s ? s->s : INVALID_SOCKET;
 }
-SOCKET next_socket(enum234 *e) {
+SOCKET next_socket(int *state) {
-    Actual_Socket s = next234(e);
+    Actual_Socket s = index234(sktree, (*state)++);
     return s ? s->s : INVALID_SOCKET;
 }