Addresses #293

Checkpoint in implementation.
Vincenzo left for the night.

git-svn-id: file:///svn/tokudb@1829 c7de825b-a66e-492c-adef-691d508d4ae1

src/lock_tree/locktree.c

@@ -8,6 +8,11 @@
 #include <brt-internal.h>
 #include <stdlib.h>
 
+static int __toku_lt_panic(toku_lock_tree *tree, int r) {
+    tree->panicked = TRUE;
+    return r;
+}
+                
 DBT __toku_lt_infinity;
 DBT __toku_lt_neg_infinity;
 
@@ -59,12 +64,62 @@ int __toku_lt_point_cmp(void* a, void* b) {
                    __toku_recreate_DBT(&point_2, y->data_payload, y->data_len));
 }
 
+static int __toku_p_free(toku_point* point) {
+    assert(point);
+    toku_free(point);
+    return 0;
+}
+
+static int __toku_p_copy(void** pdata, unsigned* plen) {
+    assert(pdata && plen);
+    unsigned len = *plen;
+    void* data = *pdata;
+
+    /* No reason to copy.  We're done already! */
+    if (!data || !len ||
+        data == toku_lt_infinity || data == toku_lt_neg_infinity) return 0;
+    //void* tempdata = toku_malloc
+    //TODO: Finish this function
+    assert(FALSE);
+}
+
+static int __toku_p_makecopy(toku_point* point) {
+    assert(point);
+    toku_lock_tree* tree = point->lt;
+
+    BOOL copy_key   = TRUE;
+    BOOL copy_data  = TRUE;
+
+    if (point->key_payload == toku_lt_infinity ||
+        point->key_payload == toku_lt_neg_infinity) {
+        copy_key = copy_data = FALSE;
+    }
+    else {
+        if (point->key_payload == NULL || point->key_len == 0) copy_key = FALSE;
+        
+    }
+    if (!tree->duplicates) copy_data = FALSE;
+    
+    assert(FALSE);
+    //TODO: FINISH THIS FUNCTION
+
+/*
+    toku_lock_tree* lt;
+    void*           key_payload;
+    u_int32_t       key_len;
+    void*           data_payload;
+    u_int32_t       data_len;
+*/
+    
+}
+
 /* Provides access to a selfwrite tree for a particular transaction.
    Returns NULL if it does not exist yet. */
 static toku_range_tree* __toku_lt_ifexist_selfwrite(toku_lock_tree* tree,
                                                     DB_TXN* txn) {
     assert(tree && txn);
-    assert(FALSE); //Not Implemented.
+    //TODO: Implement real version.
+    return tree->selfwrite;
 }
 
 /* Provides access to a selfread tree for a particular transaction.
@@ -72,7 +127,8 @@ static toku_range_tree* __toku_lt_ifexist_selfwrite(toku_lock_tree* tree,
 static toku_range_tree* __toku_lt_ifexist_selfread(toku_lock_tree* tree,
                                                    DB_TXN* txn) {
     assert(tree && txn);
-    assert(FALSE); //Not Implemented.
+    //TODO: Implement.
+    return tree->selfread;
 }
 
 /* Provides access to a selfwrite tree for a particular transaction.
@@ -80,7 +136,9 @@ static toku_range_tree* __toku_lt_ifexist_selfread(toku_lock_tree* tree,
 static int __toku_lt_selfwrite(toku_lock_tree* tree, DB_TXN* txn,
                                toku_range_tree** pselfwrite) {
     assert(tree && txn && pselfwrite);
-    assert(FALSE); //Not Implemented.
+    *pselfwrite = tree->selfwrite;
+    //TODO: Implement.
+    return 0;
 }
 
 /* Provides access to a selfread tree for a particular transaction.
@@ -88,48 +146,156 @@ static int __toku_lt_selfwrite(toku_lock_tree* tree, DB_TXN* txn,
 static int __toku_lt_selfread(toku_lock_tree* tree, DB_TXN* txn,
                               toku_range_tree** pselfread) {
     assert(tree && txn && pselfread);
-    assert(FALSE); //Not Implemented.
+    *pselfread = tree->selfread;
+    //TODO: Implement.
+    return 0;
 }
 
-static int __toku_lt_dominated(toku_lock_tree* tree, toku_range* query,
+/*
+    This function only supports non-overlapping trees.
+    Uses the standard definition of dominated from the design document.
+    Determines whether 'query' is dominated by 'rt'.
+*/
+static int __toku_lt_rt_dominates(toku_lock_tree* tree, toku_range* query,
                                   toku_range_tree* rt, BOOL* dominated) {
     assert(tree && query && rt && dominated);
+    BOOL allow_overlaps;
     toku_range  buffer[1];
     toku_range* buf = &buffer[0];
     unsigned    buflen = sizeof(buf) / sizeof(buf[0]);
     unsigned    numfound;
     int         r;
 
+    /* Sanity check. (Function only supports non-overlap range trees.) */
+    r = toku_rt_get_allow_overlaps(rt, &allow_overlaps);
+    if (r!=0) return r;
+    assert(!allow_overlaps);
+
     r = toku_rt_find(rt, query, 1, &buf, &buflen, &numfound);
     if (r!=0) return r;
     if (numfound == 0) {
         *dominated = FALSE;
         return 0;
     }
-    *dominated = (__toku_lt_point_cmp(query->left, buf[0].right) <= 0 &&
-                  __toku_lt_point_cmp(buf[0].left, query->right) <= 0);
+    assert(numfound == 1);
+    *dominated = (__toku_lt_point_cmp(query->left,  buf[0].left) >= 0 &&
+                  __toku_lt_point_cmp(query->right, buf[0].right) <= 0);
     return 0;
 }
 
-static int __toku_lt_met_at_peer(toku_lock_tree* tree, DB_TXN* self,
+/* Will Toku dominate the world? We do not know. But, this function will 
+   check whether toku_range_trees dominate a query range. */
+static int __toku_lt_dominated(toku_lock_tree *tree, toku_range *query, 
+                               toku_range_tree* rt, BOOL *dominated) {
+    int r = 0;
+    
+    assert (tree && query && dominated);
+    *dominated = FALSE;
+    
+    if (rt) r = __toku_lt_rt_dominates(tree, query, rt, dominated);
+
+    return r;
+}
+
+typedef enum
+       {TOKU_NO_CONFLICT, TOKU_MAYBE_CONFLICT, TOKU_YES_CONFLICT} toku_conflict;
+/*
+    This function checks for conflicts in the borderwrite tree.
+    If no range overlaps, there is no conflict.
+    If >= 2 ranges overlap the query then, by definition of borderwrite,
+    at least one overlapping regions must not be 'self'. Design document
+    explains why this MUST cause a conflict.
+    If exactly one range overlaps and its data == self, there is no conflict.
+    If exactly one range overlaps and its data != self, there might be a
+    conflict.  We need to check the 'peer'write table to verify.
+*/
+static int __toku_lt_borderwrite_conflict(toku_lock_tree* tree, DB_TXN* self,
                                        toku_range* query,
-                                 toku_range_tree* rt,  DB_TXN** peer) {
-    assert(tree && query && rt && peer);
+                                       toku_conflict* conflict, DB_TXN** peer) {
+    assert(tree && self && query && conflict && peer);
+    toku_range_tree* rt = tree->borderwrite;
+    assert(rt);
+    
     toku_range  buffer[2];
     toku_range* buf = &buffer[0];
     unsigned    buflen = sizeof(buf) / sizeof(buf[0]);
     unsigned    numfound;
-    unsigned    i;
     int         r;
 
     r = toku_rt_find(rt, query, 2, &buf, &buflen, &numfound);
     if (r!=0) return r;
-    for (i = 0; i < numfound; i++) {
-        if (buf[i].data == self) continue;
-        *peer = buf[i].data;
+    assert(numfound <= 2);
+    *peer = NULL;
+    if      (numfound == 2)      *conflict = TOKU_YES_CONFLICT;
+    else if (numfound == 0)      *conflict = TOKU_NO_CONFLICT;
+    else {
+        assert(numfound == 1);
+        if (buf[0].data == self) *conflict = TOKU_NO_CONFLICT;
+        else {
+            *conflict = TOKU_MAYBE_CONFLICT;
+            *peer = buf[0].data;
+        }
+    }
+    return 0;
+}
+
+/*
+    This function supports only non-overlapping trees.
+    Uses the standard definition of 'query' meets 'tree' at 'data' from the
+    design document.
+    Determines whether 'query' meets 'rt'.
+*/
+static int __toku_lt_meets(toku_lock_tree* tree, DB_TXN* self,
+                           toku_range* query, toku_range_tree* rt,  BOOL* met) {
+    assert(tree && self && query && rt && met);
+    toku_range  buffer[1];
+    toku_range* buf = &buffer[0];
+    unsigned    buflen = sizeof(buf) / sizeof(buf[0]);
+    unsigned    numfound;
+    int         r;
+    BOOL        allow_overlaps;
+
+    /* Sanity check. (Function only supports non-overlap range trees.) */
+    r = toku_rt_get_allow_overlaps(rt, &allow_overlaps);
+    if (r!=0) return r;
+    assert(!allow_overlaps);
+
+    r = toku_rt_find(rt, query, 1, &buf, &buflen, &numfound);
+    if (r!=0) return r;
+    assert(numfound == 0 || numfound == 1);
+    *met = numfound != 0;
     return 0;
+}
+
+/*
+    Utility function to implement: (from design document)
+    if K meets E at v'!=t and K meets W_v' then return failure.
+*/
+static int __toku_lt_check_borderwrite_conflict(toku_lock_tree* tree,
+                                               DB_TXN* txn, toku_range* query) {
+    assert(tree && txn && query);
+    toku_conflict conflict;
+    DB_TXN* peer;
+    toku_range_tree* borderwrite = tree->borderwrite;
+    toku_range_tree* peer_selfwrite;
+    assert(borderwrite);
+    int r;
+    
+    r = __toku_lt_borderwrite_conflict(tree, txn, query, &conflict, &peer);
+    if (r!=0) return r;
+    if (conflict == TOKU_MAYBE_CONFLICT) {
+        assert(peer);
+        peer_selfwrite = __toku_lt_ifexist_selfwrite(tree, peer);
+        assert(peer_selfwrite);
+
+        BOOL met;
+        r = __toku_lt_meets(tree, txn, query, peer_selfwrite, &met);
+        if (r!=0)         return r;
+        if (met) conflict = TOKU_YES_CONFLICT;
+        else     conflict = TOKU_NO_CONFLICT;
     }
-    *peer = NULL;
+    if (conflict == TOKU_YES_CONFLICT) return DB_LOCK_NOTGRANTED;
+    assert(conflict == TOKU_NO_CONFLICT);
     return 0;
 }
 
@@ -175,7 +341,7 @@ int toku_lt_create(toku_lock_tree** ptree, DB* db) {
     if (!ptree || !db)                                      return EINVAL;
     int r;
 
-    toku_lock_tree* temp_tree = (toku_lock_tree*)malloc(sizeof(*temp_tree));
+    toku_lock_tree* temp_tree = (toku_lock_tree*)toku_malloc(sizeof(*temp_tree));
     if (0) {
         died1:
         free(temp_tree);
@@ -186,7 +352,8 @@ int toku_lt_create(toku_lock_tree** ptree, DB* db) {
     temp_tree->db         = db;
     temp_tree->duplicates = __toku_db_is_dupsort(db);
     r = toku_rt_create(&temp_tree->mainread,
-                       __toku_lt_point_cmp, __toku_lt_txn_cmp, TRUE);
+                       __toku_lt_point_cmp, __toku_lt_txn_cmp, TRUE,
+                       toku_malloc, toku_free, toku_realloc);
     if (0) {
         died2:
         toku_rt_close(temp_tree->mainread);
@@ -194,14 +361,27 @@ int toku_lt_create(toku_lock_tree** ptree, DB* db) {
     }
     if (r!=0) goto died1;
     r = toku_rt_create(&temp_tree->borderwrite,
-                       __toku_lt_point_cmp, __toku_lt_txn_cmp, FALSE);
+                       __toku_lt_point_cmp, __toku_lt_txn_cmp, FALSE,
+                       toku_malloc, toku_free, toku_realloc);
     if (0) {
         died3:
         toku_rt_close(temp_tree->borderwrite);
         goto died2;
     }
     if (r!=0) goto died2;
+//TODO: Remove this, and use multiples per transaction
+r = toku_rt_create(&temp_tree->selfwrite,
+                   __toku_lt_point_cmp, __toku_lt_txn_cmp, FALSE,
+                   toku_malloc, toku_free, toku_realloc);
+assert(temp_tree->selfwrite);
+//TODO: Remove this, and use multiples per transaction
+r = toku_rt_create(&temp_tree->selfread,
+                   __toku_lt_point_cmp, __toku_lt_txn_cmp, TRUE,
+                   toku_malloc, toku_free, toku_realloc);
+assert(temp_tree->selfread);
+
     temp_tree->buflen = __toku_default_buflen;
+    /* Using malloc here because range trees do not use toku_malloc/free. */
     temp_tree->buf    = (toku_range*)
                         malloc(temp_tree->buflen * sizeof(toku_range));
     if (!temp_tree->buf) {
@@ -224,12 +404,6 @@ int toku_lt_close(toku_lock_tree* tree) {
 
 int toku_lt_acquire_read_lock(toku_lock_tree* tree, DB_TXN* txn,
                               DBT* key, DBT* data) {
-    if (!tree || !txn || !key)                              return EINVAL;
-    if (!tree->duplicates && data)                          return EINVAL;
-    if (tree->duplicates && !data)                          return EINVAL;
-    if (tree->duplicates && key != data &&
-                           (key == toku_lt_infinity ||
-                            key == toku_lt_neg_infinity))   return EINVAL;
     return toku_lt_acquire_range_read_lock(tree, txn, key, data, key, data);
 }
 
@@ -252,63 +426,153 @@ int toku_lt_acquire_range_read_lock(toku_lock_tree* tree, DB_TXN* txn,
     toku_point right;
     toku_range query;
     BOOL dominated;
-    toku_range_tree* selfwrite;
-    toku_range_tree* selfread;
-    toku_range_tree* borderwrite;
-    toku_range_tree* peer_selfwrite;
-    DB_TXN* peer;
     
     __toku_init_point(&left,   tree,  key_left,  data_left);
     __toku_init_point(&right,  tree,  key_right, data_right);
     __toku_init_query(&query, &left, &right);
     
-    selfwrite = __toku_lt_ifexist_selfwrite(tree, txn);
-    if (selfwrite) {
-        r = __toku_lt_dominated(tree, &query, selfwrite, &dominated);
+    /*
+        For transaction 'txn' to acquire a read-lock on range 'K'=['left','right']:
+            if 'K' is dominated by selfwrite('txn') then return success.
+            else if 'K' is dominated by selfread('txn') then return success.
+            else if 'K' meets borderwrite at 'peer' ('peer'!='txn') &&
+                    'K' meets selfwrite('peer') then return failure.
+            else
+                add 'K' to selfread('txn') and selfwrite('txn').
+                This requires merging.. see below.
+    */
+
+    /* if 'K' is dominated by selfwrite('txn') then return success. */
+    r = __toku_lt_dominated(tree, &query, 
+                            __toku_lt_ifexist_selfwrite(tree, txn), &dominated);
+    if (r || dominated) return r;
+    
+
+    /* else if 'K' is dominated by selfread('txn') then return success. */
+    r = __toku_lt_dominated(tree, &query, 
+                            __toku_lt_ifexist_selfread(tree, txn), &dominated);
+    if (r || dominated) return r; 
+
+    /*
+        else if 'K' meets borderwrite at 'peer' ('peer'!='txn') &&
+                'K' meets selfwrite('peer') then return failure.
+    */
+    r = __toku_lt_check_borderwrite_conflict(tree, txn, &query);
     if (r!=0) return r;
-        if (dominated) return 0;
-    }
-    selfread = __toku_lt_ifexist_selfread(tree, txn);
-    if (selfread) {
-        r = __toku_lt_dominated(tree, &query, selfread, &dominated);
-        if (r!=0) return r;
-        if (dominated) return 0;
-    }
-    borderwrite = tree->borderwrite;
-    if (borderwrite) {
-        r = __toku_lt_met_at_peer(tree, txn, &query, borderwrite, &peer);
-        if (r!=0) return r;
-        if (peer != NULL) {
-            peer_selfwrite = __toku_lt_ifexist_selfwrite(tree, peer);
-            assert(peer_selfwrite);
-            r = __toku_lt_met_at_peer(tree, txn, &query, peer_selfwrite, &peer);
-            if (r!=0)         return r;
-            if (peer != NULL) return DB_LOCK_NOTGRANTED;
-        }
-    }
-    /* Now need to merge, copy the memory and insert. */
 
+    /* Now need to merge, copy the memory and insert. */
     BOOL        alloc_left  = TRUE;
     BOOL        alloc_right = TRUE;
+    BOOL        copy_left   = FALSE;
     toku_range  to_insert;
     __toku_init_insert(&to_insert, &left, &right, txn);
+
+    toku_range_tree* mainread = tree->mainread;
+    assert(mainread);
+    toku_range_tree* selfread = __toku_lt_ifexist_selfread(tree, txn);
     if (selfread) {
-        //TODO: Find all that overlap in here.
-        //TODO: extend range to that, delete from selfread and mainread
-        //TODO: If left (or right) is extended/equal, copy the pointer
-        //      and unset alloc_left (or right).
+        unsigned numfound;
+        r = toku_rt_find(selfread, &query, 0, &tree->buf, &tree->buflen,
+                         &numfound);
+        if (r!=0) return r;
+        
+        /* Consolidate the new range and all the overlapping ranges */
+        
+        /** This is so important that it should go into doxygen at some point,
+            either here or in the .h file
+           
+           Memory ownership: 
+           - tree->buf is an array of toku_range's, which the lt owns
+             The contents of tree->buf are volatile (this is a buffer space
+             that we pass around to various functions, and every time we
+             invoke a new function, its previous contents may become 
+             meaningless)
+           - tree->buf[i].left, .right are toku_points (ultimately a struct), 
+             also owned by lt. We gave a pointer only to this memory to the 
+             range tree earlier when we inserted a range, but the range tree
+             does not own it!
+           - tree->buf[i].{left,right}.{key_payload,data_payload} is owned by
+             the lt, we made copies from the DB at some point
+           - to_insert we own (it's static)
+           - to_insert.left, .right are toku_point's, and we own them.
+             If we have consolidated, we own them because we had allocated
+             them earlier, but
+             if we have not consolidated we need to gain ownership now: 
+             we will gain ownership by copying all payloads and 
+             allocating the points. 
+            -to_insert.{left,right}.{key_payload, data_payload} are owned by lt,
+             we made copies from the DB at consolidation time 
+        */   
+        unsigned i;
+        for (i = 0; i < numfound; i++) {
+            /* Delete overlapping ranges from selfread ... */
+            r = toku_rt_delete(selfread, &(tree->buf[i]));
+            if (r!=0) return __toku_lt_panic(tree,r);
+            /* ... and mainread.
+               Growth direction: if we had no overlaps, the next two lines
+               should be commented out */
+            r = toku_rt_delete(mainread, &(tree->buf[i]));
+            if (r!=0) return __toku_lt_panic(tree,r);
+        }
+
+        for (i = 0; i < numfound; i++) {
+            /* Find the extreme left end-point among overlapping ranges */
+            if (__toku_lt_point_cmp(tree->buf[i].left,to_insert.left) 
+                <= 0) {
+                assert(tree->buf[i].left != to_insert.left);
+                assert(tree->buf[i].left != to_insert.right);
+                if (alloc_left)     alloc_left  = FALSE;
+                to_insert.left     = tree->buf[i].left;
+            }
+            /* Find the extreme right end-point */
+            if (__toku_lt_point_cmp(tree->buf[i].right,to_insert.right)
+                >= 0) {
+                assert(tree->buf[i].right != to_insert.left ||
+                       (tree->buf[i].left  == to_insert.left &&
+                        tree->buf[i].left  == tree->buf[i].right));
+                assert(tree->buf[i].right != to_insert.right);
+                if (alloc_right)    alloc_right = FALSE;
+                to_insert.right    = tree->buf[i].right;
+            }
         }
+
+        BOOL free_left;
+        BOOL free_right;
+        for (i = 0; i < numfound; i++) {
+            /*
+               We will maintain the invariant: (separately for read and write
+               environments)
+               (__toku_lt_point_cmp(a, b) == 0 && a.txn == b.txn) => a == b
+            */
+            /* Do not double-free. */
+            if (tree->buf[i].left == tree->buf[i].right) free_right = FALSE;
+            else {
+                free_right = (tree->buf[i].right != to_insert.left &&
+                              tree->buf[i].right != to_insert.right);
+            }
+            free_left = (tree->buf[i].left != to_insert.left &&
+                         tree->buf[i].left != to_insert.right);
+            if (free_left)  __toku_p_free(tree->buf[i].left);
+            if (free_right) __toku_p_free(tree->buf[i].right);
+        }
+    }
+    
     if (alloc_left && alloc_right && __toku_lt_point_cmp(&left, &right) == 0) {
         alloc_right = FALSE;
+        copy_left   = TRUE;
     }
     if (alloc_left) {
         r = __toku_p_makecopy(&left);
         assert(r==0); //TODO: Error Handling instead of assert
     }
     if (alloc_right) {
+        assert(!copy_left);
         r = __toku_p_makecopy(&right);
         assert(r==0); //TODO: Error Handling instead of assert
     }
+    else if (copy_left) {
+        //TODO: Copy the pointer.
+    }
     if (!selfread) {
         r = __toku_lt_selfread(tree, txn, &selfread);
         assert(r==0); //TODO: Error Handling instead of assert
@@ -335,39 +599,24 @@ int toku_lt_acquire_write_lock(toku_lock_tree* tree, DB_TXN* txn,
     toku_point left;
     toku_range query;
     BOOL dominated;
-    toku_range_tree* selfwrite;
     toku_range_tree* mainread;
-    toku_range_tree* borderwrite;
-    toku_range_tree* peer_selfwrite;
-    DB_TXN*          peer;
     
     __toku_init_point(&left,   tree,  key, data);
     __toku_init_query(&query, &left, &left);
 
-    selfwrite = __toku_lt_ifexist_selfwrite(tree, txn);
-    if (selfwrite) {
-        r = __toku_lt_dominated(tree, &query, selfwrite, &dominated);
-        if (r!=0) return r;
-        if (dominated) return 0;
-    }
-    mainread = tree->mainread;
-    if (mainread) {
-        r = __toku_lt_met_at_peer(tree, txn, &query, mainread, &peer);
-        if (r!=0)       return r;
-        if (peer!=NULL) return DB_LOCK_NOTGRANTED;
-    }
-    borderwrite = tree->borderwrite;
-    if (borderwrite) {
-        r = __toku_lt_met_at_peer(tree, txn, &query, borderwrite, &peer);
-        if (r!=0) return r;
-        if (peer != NULL) {
-            peer_selfwrite = __toku_lt_ifexist_selfwrite(tree, peer);
-            assert(peer_selfwrite);
-            r = __toku_lt_met_at_peer(tree, txn, &query, peer_selfwrite, &peer);
+    /* if 'K' is dominated by selfwrite('txn') then return success. */
+    r = __toku_lt_dominated(tree, &query, 
+                            __toku_lt_ifexist_selfwrite(tree, txn), &dominated);
+    if (r || dominated) return r;
+    
+    /* else if 'K' is dominated by selfread('txn') then return success. */
+    mainread = tree->mainread; assert(mainread);
+    r = __toku_lt_dominated(tree, &query, mainread, &dominated);
+    if (r || dominated) return r; 
+
+    r = __toku_lt_check_borderwrite_conflict(tree, txn, &query);
     if (r!=0) return r;
-            if (peer != NULL) return DB_LOCK_NOTGRANTED;
-        }
-    }
+
     /* Now need to copy the memory and insert. */
     assert(FALSE);  //Not implemented yet.
 }

src/lock_tree/locktree.h

@@ -13,6 +13,10 @@ typedef struct {
     BOOL                duplicates;
     toku_range_tree*    mainread;
     toku_range_tree*    borderwrite;
+    //TODO: Remove this tree and have one per transaction.
+    toku_range_tree*    selfread;
+    //TODO: Remove this tree and have one per transaction.
+    toku_range_tree*    selfwrite;
     toku_range*         buf;
     unsigned            buflen;
     BOOL                panicked;