e576bb2002-10-11Martin Nilsson /* || This file is part of Pike. For copyright information see COPYRIGHT. || Pike is distributed under GPL, LGPL and MPL. See the file COPYING || for more information.
1cbb892011-04-25Martin Stjernholm || $Id$
e576bb2002-10-11Martin Nilsson */
1b10db2002-10-08Martin Nilsson 
bdf6692001-12-10Martin Stjernholm /* The lower level api for using rbtree. This is in a separate file * since it's quite macro heavy. * * Created 2001-04-27 by Martin Stjernholm */ #ifndef RBTREE_LOW_H #define RBTREE_LOW_H #include "rbtree.h" /* A sliced stack is used to track the way down in a tree, so we can * back up again easily while rebalancing it. The first slice is * allocated on the C stack. */ #define STACK_SLICE_SIZE 20 /* This is in the worst possible case enough for trees of size * 2^(20/2) = 1024 before allocating another slice, but in the typical * case it's enough for trees with up to about 2^(20-1) = 524288 * elements. */ struct rbstack_slice { #ifdef RB_STATS size_t depth, maxdepth; #endif struct rbstack_slice *up; struct rb_node_hdr *stack[STACK_SLICE_SIZE]; }; struct rbstack_ptr { struct rbstack_slice *slice; size_t ssp; /* Only zero when the stack is empty. */ }; void rbstack_push (struct rbstack_ptr *rbstack, struct rb_node_hdr *node); void rbstack_pop (struct rbstack_ptr *rbstack); void rbstack_up (struct rbstack_ptr *rbstack); void rbstack_up_to_root (struct rbstack_ptr *rbstack); void rbstack_free (struct rbstack_ptr *rbstack); void rbstack_insert (struct rbstack_ptr *top, struct rbstack_ptr *pos, struct rb_node_hdr *node); void rbstack_assign (struct rbstack_ptr *target, struct rbstack_ptr *source); void rbstack_copy (struct rbstack_ptr *target, struct rbstack_ptr *source); void rbstack_shift (struct rbstack_ptr rbstack, struct rb_node_hdr *oldbase, struct rb_node_hdr *newbase); #define RBSTACK_INIT(rbstack) \ struct rbstack_slice PIKE_CONCAT3 (_, rbstack, _top_) = { \ DO_IF_RB_STATS (0 COMMA 0 COMMA) \ NULL, \
b6dcfd2002-08-28Henrik Grubbström (Grubba)  {NULL,} \
bdf6692001-12-10Martin Stjernholm  }; \ struct rbstack_ptr rbstack = { \ (PIKE_CONCAT3 (_, rbstack, _top_).up = NULL, \ &PIKE_CONCAT3 (_, rbstack, _top_)), \ 0 \ } #define RBSTACK_PUSH(rbstack, node) do { \ if ((rbstack).ssp < STACK_SLICE_SIZE) { \ (rbstack).slice->stack[(rbstack).ssp++] = (node); \ } \ else rbstack_push (&(rbstack), node); \ DO_IF_RB_STATS ( \ if (++(rbstack).slice->depth > (rbstack).slice->maxdepth) \ (rbstack).slice->maxdepth = (rbstack).slice->depth; \ ); \ } while (0) #define RBSTACK_POP(rbstack, node) do { \ if ((rbstack).ssp) { \ (node) = (rbstack).slice->stack[--(rbstack).ssp]; \ DO_IF_RB_STATS ((rbstack).slice->depth--); \ if (!(rbstack).ssp && (rbstack).slice->up) \ rbstack_pop (&(rbstack)); \ } \ else (node) = NULL; \ } while (0) #define RBSTACK_POP_IGNORE(rbstack) do { \ if ((rbstack).ssp && !--(rbstack).ssp) { \ DO_IF_RB_STATS ((rbstack).slice->depth--); \ if ((rbstack).slice->up) \ rbstack_pop (&(rbstack)); \ } \ } while (0) #define RBSTACK_UP(rbstack, node) do { \ if ((rbstack).ssp) { \ (node) = (rbstack).slice->stack[--(rbstack).ssp]; \ if (!(rbstack).ssp && (rbstack).slice->up) \ rbstack_up (&(rbstack)); \ } \ else (node) = NULL; \ } while (0) #define RBSTACK_UP_IGNORE(rbstack) do { \ if ((rbstack).ssp && !--(rbstack).ssp && (rbstack).slice->up) \ rbstack_up (&(rbstack)); \ } while (0) #define RBSTACK_PEEK(rbstack) \ ((rbstack).ssp ? (rbstack).slice->stack[(rbstack).ssp - 1] : NULL) #define RBSTACK_POKE(rbstack, node) do { \
5aad932002-08-15Marcus Comstedt  DO_IF_DEBUG (if (!(rbstack).ssp) Pike_fatal ("Using free stack pointer.\n")); \
bdf6692001-12-10Martin Stjernholm  (rbstack).slice->stack[(rbstack).ssp - 1] = (node); \ } while (0) #define RBSTACK_UP_TO_ROOT(rbstack, node) do { \ if ((rbstack).ssp) { \ rbstack_up_to_root (&(rbstack)); \ (node) = (rbstack).slice->stack[0]; \ } \ } while (0) #define RBSTACK_FREE(rbstack) do { \ if ((rbstack).ssp) { \ if ((rbstack).slice->up) rbstack_free (&(rbstack)); \ (rbstack).ssp = 0; \ } \ DO_IF_RB_STATS ( \ rb_num_tracks++; \ rb_track_depth += (rbstack).slice->maxdepth; \ if ((rbstack).slice->maxdepth > rb_max_depth) \ rb_max_depth = (rbstack).slice->maxdepth; \ (rbstack).slice->depth = (rbstack).slice->maxdepth = 0; \ ); \ } while (0) #define RBSTACK_FREE_SET_ROOT(rbstack, node) do { \ if ((rbstack).ssp) { \ if ((rbstack).slice->up) rbstack_free (&(rbstack)); \
d192352004-05-28Martin Stjernholm  (rbstack).ssp = 0; \
bdf6692001-12-10Martin Stjernholm  (node) = (rbstack).slice->stack[0]; \ } \ DO_IF_RB_STATS ( \ rb_num_tracks++; \ rb_track_depth += (rbstack).slice->maxdepth; \ if ((rbstack).slice->maxdepth > rb_max_depth) \ rb_max_depth = (rbstack).slice->maxdepth; \ (rbstack).slice->depth = (rbstack).slice->maxdepth = 0; \ ); \ } while (0) void low_rb_init_root (struct rb_node_hdr *new_root); void low_rb_link_at_prev (struct rb_node_hdr **root, struct rbstack_ptr rbstack, struct rb_node_hdr *new); void low_rb_link_at_next (struct rb_node_hdr **root, struct rbstack_ptr rbstack, struct rb_node_hdr *new); struct rb_node_hdr *low_rb_unlink_with_move (struct rb_node_hdr **root, struct rbstack_ptr *rbstack_ptr, int keep_rbstack, size_t node_size); void low_rb_unlink_without_move (struct rb_node_hdr **root, struct rbstack_ptr *rbstack_ptr, int keep_rbstack); void low_rb_build_stack (struct rb_node_hdr *root, struct rb_node_hdr *node, struct rbstack_ptr *rbstack); #if defined (PIKE_DEBUG) || defined (TEST_MULTISET) typedef void dump_data_fn (struct rb_node_hdr *node, void *extra); void debug_dump_rb_tree (struct rb_node_hdr *root, dump_data_fn *dump_data, void *extra); void debug_dump_rbstack (struct rbstack_ptr rbstack, struct rbstack_ptr *pos); void debug_check_rb_tree (struct rb_node_hdr *root, dump_data_fn *dump_data, void *extra); void debug_check_rbstack (struct rb_node_hdr *root, struct rbstack_ptr rbstack); #endif /* Traverses the tree in depth-first order: * push Run when entering the node. Preceded by an enter_* label. * p_leaf Run when the prev pointer of the node isn't a subtree. * p_sub Run when the prev pointer of the node is a subtree. * between Run after the prev subtree has been recursed and before * the next subtree is examined. Preceded by a between_* * label. * n_leaf Run when the next pointer of the node isn't a subtree. * n_sub Run when the next pointer of the node is a subtree. * pop Run when leaving the node. Preceded by a leave_* label. */ #define LOW_RB_TRAVERSE(label, rbstack, node, push, p_leaf, p_sub, \ between, n_leaf, n_sub, pop) \ do { \ struct rb_node_hdr *rb_last_; \ DO_IF_RB_STATS (rb_num_traverses++); \ if (node) { \ PIKE_CONCAT (enter_, label): \ DO_IF_RB_STATS (rb_num_traverse_ops++); \ {push;} \ if ((node)->flags & RB_THREAD_PREV) \ {p_leaf;} \ else { \ {p_sub;} \ RBSTACK_PUSH (rbstack, node); \ (node) = (node)->prev; \ goto PIKE_CONCAT (enter_, label); \ } \ PIKE_CONCAT (between_, label): \ {between;} \ if ((node)->flags & RB_THREAD_NEXT) \ {n_leaf;} \ else { \ {n_sub;} \ RBSTACK_PUSH (rbstack, node); \ (node) = (node)->next; \ goto PIKE_CONCAT (enter_, label); \ } \ while (1) { \ PIKE_CONCAT (leave_, label): \ DO_IF_RB_STATS (rb_num_traverse_ops++); \ {pop;} \ rb_last_ = (node); \ RBSTACK_POP (rbstack, node); \ if (!(node)) break; \ if (rb_last_ == (node)->prev) \ goto PIKE_CONCAT (between_, label); \ } \ } \ } while (0) #define LOW_RB_DEBUG_TRAVERSE(label, rbstack, node, push, p_leaf, p_sub, \ between, n_leaf, n_sub, pop) \ do { \ size_t PIKE_CONCAT (depth_, label) = 0; \ LOW_RB_TRAVERSE( \ label, rbstack, node, \ fprintf (stderr, "%*s%p enter\n", \ PIKE_CONCAT (depth_, label)++, "", node); {push;}, \ fprintf (stderr, "%*s%p prev leaf\n", \ PIKE_CONCAT (depth_, label), "", node); {p_leaf;}, \ fprintf (stderr, "%*s%p prev subtree\n", \ PIKE_CONCAT (depth_, label), "", node); {p_sub;}, \ fprintf (stderr, "%*s%p between\n", \ PIKE_CONCAT (depth_, label) - 1, "", node); {between;}, \ fprintf (stderr, "%*s%p next leaf\n", \ PIKE_CONCAT (depth_, label), "", node); {n_leaf;}, \ fprintf (stderr, "%*s%p next subtree\n", \ PIKE_CONCAT (depth_, label), "", node); {n_sub;}, \ fprintf (stderr, "%*s%p leave\n", \ --PIKE_CONCAT (depth_, label), "", node); {pop;}); \ } while (0) /* The `cmp' code should set the variable cmp_res to the result of the * comparison between the key and the current node `node'. */ #define LOW_RB_FIND(node, cmp, got_lt, got_eq, got_gt) \ do { \ int cmp_res, found_eq_ = 0; \ DO_IF_RB_STATS ( \ size_t stat_depth_count_ = 0; \ rb_num_finds++; \ ); \ while (1) { \
5aad932002-08-15Marcus Comstedt  DO_IF_DEBUG (if (!node) Pike_fatal ("Recursing into null node.\n")); \
bdf6692001-12-10Martin Stjernholm  DO_IF_RB_STATS ( \ if (++stat_depth_count_ > rb_max_depth) \ rb_max_depth = stat_depth_count_; \ rb_find_depth++; \ ); \ {cmp;} \ if (cmp_res < 0) \ if ((node)->flags & RB_THREAD_PREV) \ if (found_eq_) \ (node) = (node)->prev; \ else { \ {got_gt;} \ break; \ } \ else { \ (node) = (node)->prev; \ continue; \ } \ else \ if ((node)->flags & RB_THREAD_NEXT) \ if (!cmp_res) \ {} \ else { \ {got_lt;} \ break; \ } \ else { \ if (!cmp_res) found_eq_ = 1; \ (node) = (node)->next; \ continue; \ } \ {got_eq;} \ break; \ } \ } while (0) /* Variant of LOW_RB_FIND that assumes that `cmp' never returns 0. */ #define LOW_RB_FIND_NEQ(node, cmp, got_lt, got_gt) \ do { \ int cmp_res; \ DO_IF_RB_STATS ( \ size_t stat_depth_count_ = 0; \ rb_num_finds++; \ ); \ while (1) { \
5aad932002-08-15Marcus Comstedt  DO_IF_DEBUG (if (!node) Pike_fatal ("Recursing into null node.\n")); \
bdf6692001-12-10Martin Stjernholm  DO_IF_RB_STATS ( \ if (++stat_depth_count_ > rb_max_depth) \ rb_max_depth = stat_depth_count_; \ rb_find_depth++; \ ); \ {cmp;} \ if (cmp_res < 0) { \ if ((node)->flags & RB_THREAD_PREV) { \ {got_gt;} \ break; \ } \ (node) = (node)->prev; \ } \ else { \
5aad932002-08-15Marcus Comstedt  DO_IF_DEBUG (if (!cmp_res) Pike_fatal ("cmp_res 0 not expected.\n")); \
bdf6692001-12-10Martin Stjernholm  if ((node)->flags & RB_THREAD_NEXT) { \ {got_lt;} \ break; \ } \ (node) = (node)->next; \ } \ } \ } while (0) /* Tracks the way down a tree to a specific node and updates the stack * as necessary for low_rb_link_* and low_rb_unlink_*. */ #define LOW_RB_TRACK(rbstack, node, cmp, got_lt, got_eq, got_gt) \ do { \ DO_IF_DEBUG ( \
5aad932002-08-15Marcus Comstedt  if (RBSTACK_PEEK (rbstack)) Pike_fatal ("The stack is not empty.\n"); \
bdf6692001-12-10Martin Stjernholm  ); \ DO_IF_RB_STATS (rb_num_finds--); \ LOW_RB_FIND ( \ node, \ { \ DO_IF_RB_STATS (rb_find_depth--); \ RBSTACK_PUSH (rbstack, node); \ {cmp;} \ }, \ got_lt, \ { \ while ((node) != RBSTACK_PEEK (rbstack)) \ RBSTACK_POP_IGNORE (rbstack); \ {got_eq;} \ }, got_gt); \ } while (0) #define LOW_RB_TRACK_NEQ(rbstack, node, cmp, got_lt, got_gt) \ do { \ DO_IF_DEBUG ( \
5aad932002-08-15Marcus Comstedt  if (RBSTACK_PEEK (rbstack)) Pike_fatal ("The stack is not empty.\n"); \
bdf6692001-12-10Martin Stjernholm  ); \ DO_IF_RB_STATS (rb_num_finds--); \ LOW_RB_FIND_NEQ ( \ node, \ { \ DO_IF_RB_STATS (rb_find_depth--); \ RBSTACK_PUSH (rbstack, node); \ {cmp;} \ }, \ got_lt, got_gt); \ } while (0) /* Goes to the first node in a tree while keeping the stack updated. */ #define LOW_RB_TRACK_FIRST(rbstack, node) \ do { \ DO_IF_DEBUG ( \
5aad932002-08-15Marcus Comstedt  if (RBSTACK_PEEK (rbstack)) Pike_fatal ("The stack is not empty.\n"); \
bdf6692001-12-10Martin Stjernholm  ); \ DO_IF_RB_STATS (rb_num_sidetracks++); \ if (node) { \ struct rb_node_hdr *rb_prev_ = node->prev; \ RBSTACK_PUSH (rbstack, node); \ DO_IF_RB_STATS (rb_num_sidetrack_ops++); \ while (rb_prev_) { \ RBSTACK_PUSH (rbstack, node = rb_prev_); \ DO_IF_RB_STATS (rb_num_sidetrack_ops++); \ rb_prev_ = node->prev; \ } \ } \ } while (0) /* Goes to the next node in order while keeping the stack updated. */ #define LOW_RB_TRACK_NEXT(rbstack, node) \ do { \ DO_IF_DEBUG ( \ if (node != RBSTACK_PEEK (rbstack)) \
5aad932002-08-15Marcus Comstedt  Pike_fatal ("Given node is not on top of stack.\n"); \
bdf6692001-12-10Martin Stjernholm  ); \ DO_IF_RB_STATS (rb_num_sidetracks++); \ if (node->flags & RB_THREAD_NEXT) { \ struct rb_node_hdr *rb_next_ = node->next; \ while ((node = RBSTACK_PEEK (rbstack)) != rb_next_) { \ RBSTACK_POP_IGNORE (rbstack); \ DO_IF_RB_STATS (rb_num_sidetrack_ops++); \ } \ } \ else { \ node = node->next; \ while (1) { \ RBSTACK_PUSH (rbstack, node); \ DO_IF_RB_STATS (rb_num_sidetrack_ops++); \ if (node->flags & RB_THREAD_PREV) break; \ node = node->prev; \ } \ } \ } while (0) /* Goes to the previous node in order while keeping the stack updated. */ #define LOW_RB_TRACK_PREV(rbstack, node) \ do { \ DO_IF_DEBUG ( \ if (node != RBSTACK_PEEK (rbstack)) \
5aad932002-08-15Marcus Comstedt  Pike_fatal ("Given node is not on top of stack.\n"); \
bdf6692001-12-10Martin Stjernholm  ); \ DO_IF_RB_STATS (rb_num_sidetracks++); \ if (node->flags & RB_THREAD_PREV) { \ struct rb_node_hdr *rb_prev_ = node->prev; \ while ((node = RBSTACK_PEEK (rbstack)) != rb_prev_) { \ RBSTACK_POP_IGNORE (rbstack); \ DO_IF_RB_STATS (rb_num_sidetrack_ops++); \ } \ } \ else { \ node = node->prev; \ while (1) { \ RBSTACK_PUSH (rbstack, node); \ DO_IF_RB_STATS (rb_num_sidetrack_ops++); \ if (node->flags & RB_THREAD_NEXT) break; \ node = node->next; \ } \ } \ } while (0) /* An alternative to rb_insert, which might or might not insert the * newly created node. This one compares nodes like LOW_RB_FIND and * will only run the code `insert' when a new node actually is to be * inserted, otherwise it runs the code `replace' on the matching * existing node. */ #define LOW_RB_INSERT(tree, node, cmp, insert, replace) \ do { \ int rb_ins_type_; \ RBSTACK_INIT (rbstack); \ if (((node) = *(tree))) { \ LOW_RB_TRACK ( \ rbstack, node, cmp, \ { \ rb_ins_type_ = 1; /* Got less - link at next. */ \ }, { \ rb_ins_type_ = 0; /* Got equal - replace. */ \ {replace;} \ RBSTACK_FREE (rbstack); \ }, { \ rb_ins_type_ = 2; /* Got greater - link at prev. */ \ }); \ } \ else rb_ins_type_ = 3; \ if (rb_ins_type_) { \ DO_IF_DEBUG ((node) = 0); \ {insert;} \ switch (rb_ins_type_) { \ case 1: low_rb_link_at_next ((tree), rbstack, (node)); break; \ case 2: low_rb_link_at_prev ((tree), rbstack, (node)); break; \ case 3: low_rb_init_root (*(tree) = (node)); break; \ } \ } \ } while (0) /* Merges the two trees a and b in linear time (no more, no less). The * operation argument describes the way to merge, like the one given * to merge() in array.c. cmp does the comparison between a and b to * cmp_res, copy_a and copy_b copy the nodes a and b resp, to * new_node. free_a and free_b free the nodes a and b resp. prep_a and * prep_b is run for every visited node in a and b resp, before any of * the other code blocks. * * The result in res is a list linked by the next pointers, and length * is set to the length of it. These are suitable for rb_make_tree. * * NB: It doesn't handle making duplicates of the same node, i.e. * PIKE_ARRAY_OP_A without PIKE_ARRAY_OP_SKIP_A. Not a problem since * none of the currently defined operations use that. */ #define LOW_RB_MERGE(label, a, b, res, length, operation, \ prep_a, prep_b, cmp, copy_a, free_a, copy_b, free_b) \ do { \ struct rb_node_hdr *new_node; \ int cmp_res, op_ = 0; /* Init only to avoid warnings. */ \ /* Traverse backwards so that the merge "gravitates" towards the */ \ /* end when duplicate entries are processed, e.g. */ \ /* (<1:1, 1:2>) | (<1:3>) produces (<1:1, 1:3>) and not */ \ /* (<1:3, 1:2>). */ \ \ a = rb_last (a); \ b = rb_last (b); \ res = 0; \ \ while (1) { \ /* A bit quirky code to avoid expanding the code blocks more */ \ /* than once. */ \ if (a) {prep_a;} \ if (b) { \ {prep_b;} \ if (a) { \ {cmp;} \ /* Result reversed due to backward direction. */ \ if (cmp_res > 0) \ op_ = operation >> 8; \ else if (cmp_res < 0) \ op_ = operation; \ else \ op_ = operation >> 4; \ } \ else if (operation & PIKE_ARRAY_OP_B) \ goto PIKE_CONCAT (label, _copy_b); \ else \ goto PIKE_CONCAT (label, _free_b); \ } \ else \ if (a) \ if (operation & (PIKE_ARRAY_OP_A << 8)) \ goto PIKE_CONCAT (label, _copy_a); \ else \ goto PIKE_CONCAT (label, _free_a); \ else \ break; \ \ if (op_ & PIKE_ARRAY_OP_B) { \ PIKE_CONCAT (label, _copy_b):; \ {copy_b;} \ new_node->next = res, res = new_node; \ length++; \ b = rb_prev (b); \ } \ else if (op_ & PIKE_ARRAY_OP_SKIP_B) { \ PIKE_CONCAT (label, _free_b):; \ new_node = rb_prev (b); \ {free_b;} \ b = new_node; \ } \ \ if (a) { \ if (op_ & PIKE_ARRAY_OP_A) { \ if (!(op_ & PIKE_ARRAY_OP_B)) { \ PIKE_CONCAT (label, _copy_a):; \ {copy_a;} \ new_node->next = res, res = new_node; \ length++; \ a = rb_prev (a); \ } \ } \ else if (op_ & PIKE_ARRAY_OP_SKIP_A) { \ PIKE_CONCAT (label, _free_a):; \ new_node = rb_prev (a); \ {free_a;} \ a = new_node; \ } \ } \ } \ } while (0) #endif /* RBTREE_H */