|
| 1 | +import Debug "mo:base/Debug"; |
| 2 | +import Nat32 "mo:base/Nat32"; |
| 3 | +import Nat16 "mo:base/Nat16"; |
| 4 | +import Nat64 "mo:base/Nat64"; |
| 5 | +import Nat8 "mo:base/Nat8"; |
| 6 | +import Iter "mo:base/Iter"; |
| 7 | + |
| 8 | +import MemoryRegion "mo:memory-region/MemoryRegion"; |
| 9 | +import Itertools "mo:itertools/Iter"; |
| 10 | + |
| 11 | +import V0 "V0"; |
| 12 | +import V0_0_1 "V0_0_1"; |
| 13 | + |
| 14 | +module Migrations { |
| 15 | + |
| 16 | + // should update to the latest version |
| 17 | + public type MemoryBTree = V0_0_1.MemoryBTree; |
| 18 | + public type Leaf = V0_0_1.Leaf; |
| 19 | + public type Branch = V0_0_1.Branch; |
| 20 | + |
| 21 | + public type VersionedMemoryBTree = { |
| 22 | + #v0 : V0.MemoryBTree; |
| 23 | + #v0_0_1 : V0_0_1.MemoryBTree; |
| 24 | + }; |
| 25 | + |
| 26 | + public type StableStore = VersionedMemoryBTree; |
| 27 | + type Address = Nat; |
| 28 | + |
| 29 | + public func get_depth(btree : MemoryBTree, node_address : Nat) : Nat { |
| 30 | + let depth = MemoryRegion.loadNat8(btree.branches, node_address + 3) |> Nat8.toNat(_); |
| 31 | + |
| 32 | + depth; |
| 33 | + }; |
| 34 | + |
| 35 | + public func has_leaves(btree : MemoryBTree, branch_address : Nat) : Bool { |
| 36 | + let depth = get_depth(btree, branch_address); |
| 37 | + depth == 2; |
| 38 | + }; |
| 39 | + |
| 40 | + public func CHILDREN_START(btree : MemoryBTree) : Nat { |
| 41 | + 64 + ((btree.node_capacity - 1) * 8); |
| 42 | + }; |
| 43 | + public func get_child_offset(btree : MemoryBTree, branch_address : Nat, i : Nat) : Nat { |
| 44 | + branch_address + CHILDREN_START(btree) + (i * 8); |
| 45 | + }; |
| 46 | + public func get_child(btree : MemoryBTree, branch_address : Nat, i : Nat) : ?Nat { |
| 47 | + |
| 48 | + MemoryRegion.loadNat64(btree.branches, get_child_offset(btree, branch_address, i)) |
| 49 | + |> ?Nat64.toNat(_); |
| 50 | + }; |
| 51 | + |
| 52 | + public func get_min_leaf_address(btree : MemoryBTree) : Nat { |
| 53 | + var curr = btree.root; |
| 54 | + var is_address_a_leaf = btree.is_root_a_leaf; |
| 55 | + |
| 56 | + loop { |
| 57 | + switch (is_address_a_leaf) { |
| 58 | + case (false) { |
| 59 | + let ?first_child = get_child(btree, curr, 0) else Debug.trap("get_min_leaf: accessed a null value"); |
| 60 | + is_address_a_leaf := has_leaves(btree, curr); |
| 61 | + curr := first_child; |
| 62 | + }; |
| 63 | + case (true) return curr; |
| 64 | + }; |
| 65 | + }; |
| 66 | + }; |
| 67 | + |
| 68 | + public func get_kv_address_offset(leaf_address : Nat, i : Nat) : Nat { |
| 69 | + leaf_address + 64 + (i * 8); |
| 70 | + }; |
| 71 | + |
| 72 | + public func leaf_get_kv_address(btree : MemoryBTree, address : Nat, i : Nat) : ?Nat { |
| 73 | + let kv_address_offset = get_kv_address_offset(address, i); |
| 74 | + let opt_id = MemoryRegion.loadNat64(btree.leaves, kv_address_offset); |
| 75 | + |
| 76 | + if (opt_id == 0x00) null else ?(Nat64.toNat(opt_id)); |
| 77 | + }; |
| 78 | + |
| 79 | + public func leaf_get_count(btree : MemoryBTree, address : Nat) : Nat { |
| 80 | + MemoryRegion.loadNat16(btree.leaves, address + 6) |> Nat16.toNat(_); |
| 81 | + }; |
| 82 | + public func leaf_get_kv_address_offset(leaf_address : Nat, i : Nat) : Nat { |
| 83 | + leaf_address + 64 + (i * 8); |
| 84 | + }; |
| 85 | + |
| 86 | + public func leaf_get_next(btree : MemoryBTree, address : Nat) : ?Nat { |
| 87 | + |
| 88 | + let next = MemoryRegion.loadNat64(btree.leaves, address + 24); |
| 89 | + if (next == 0x00) return null; |
| 90 | + ?Nat64.toNat(next); |
| 91 | + }; |
| 92 | + |
| 93 | + public func kv_block_addresses(btree : MemoryBTree) : Iter.Iter<Address> { |
| 94 | + |
| 95 | + let min_leaf = get_min_leaf_address(btree); |
| 96 | + var i = 0; |
| 97 | + var leaf_count = leaf_get_count(btree, min_leaf); |
| 98 | + var var_leaf = ?min_leaf; |
| 99 | + |
| 100 | + object { |
| 101 | + public func next() : ?Address { |
| 102 | + let ?leaf = var_leaf else return null; |
| 103 | + |
| 104 | + if (i >= leaf_count) { |
| 105 | + switch (leaf_get_next(btree, leaf)) { |
| 106 | + case (null) var_leaf := null; |
| 107 | + case (?next_address) { |
| 108 | + var_leaf := ?next_address; |
| 109 | + leaf_count := leaf_get_count(btree, leaf); |
| 110 | + }; |
| 111 | + }; |
| 112 | + |
| 113 | + i := 0; |
| 114 | + return next(); |
| 115 | + }; |
| 116 | + |
| 117 | + let address = leaf_get_kv_address(btree, leaf, i); |
| 118 | + i += 1; |
| 119 | + return address; |
| 120 | + }; |
| 121 | + }; |
| 122 | + |
| 123 | + }; |
| 124 | + |
| 125 | + public func upgrade(versions : VersionedMemoryBTree) : VersionedMemoryBTree { |
| 126 | + switch (versions) { |
| 127 | + case (#v0(v0)) { |
| 128 | + let values = MemoryRegion.new(); |
| 129 | + |
| 130 | + let VALUES_REGION_ID_ADDRESS = 32; |
| 131 | + MemoryRegion.storeNat32(v0.data, VALUES_REGION_ID_ADDRESS, Nat32.fromNat(MemoryRegion.id(values))); |
| 132 | + |
| 133 | + // move all values from data region to values region |
| 134 | + // might not upgrade if the data is too large |
| 135 | + |
| 136 | + let REFERENCE_COUNT_START = 0; |
| 137 | + let KEY_SIZE_START = 1; |
| 138 | + let VAL_POINTER_START = 3; |
| 139 | + let VAL_SIZE_START = 11; |
| 140 | + let KEY_BLOB_START = 15; |
| 141 | + |
| 142 | + let BLOCK_ENTRY_SIZE = 15; |
| 143 | + |
| 144 | + var key_block_address = 64; |
| 145 | + |
| 146 | + for (i in Itertools.range(0, v0.count)) { |
| 147 | + let key_size = MemoryRegion.loadNat16(v0.data, key_block_address + KEY_SIZE_START) |> Nat16.toNat(_); |
| 148 | + let val_size = MemoryRegion.loadNat32(v0.data, key_block_address + VAL_SIZE_START) |> Nat32.toNat(_); |
| 149 | + let val_address = MemoryRegion.loadNat64(v0.data, key_block_address + VAL_POINTER_START) |> Nat64.toNat(_); |
| 150 | + |
| 151 | + let val_blob = MemoryRegion.loadBlob(v0.data, val_address, val_size); |
| 152 | + MemoryRegion.deallocate(v0.data, val_address, val_size); |
| 153 | + |
| 154 | + let new_val_address = MemoryRegion.addBlob(values, val_blob); |
| 155 | + |
| 156 | + MemoryRegion.storeNat64(v0.data, key_block_address + VAL_POINTER_START, Nat64.fromNat(new_val_address)); |
| 157 | + |
| 158 | + key_block_address += BLOCK_ENTRY_SIZE + key_size + val_size; |
| 159 | + |
| 160 | + }; |
| 161 | + |
| 162 | + #v0_0_1({ |
| 163 | + v0 with values; |
| 164 | + var count = v0.count; |
| 165 | + var root = v0.root; |
| 166 | + var branch_count = v0.branch_count; |
| 167 | + var leaf_count = v0.leaf_count; |
| 168 | + var depth = v0.depth; |
| 169 | + var is_root_a_leaf = v0.is_root_a_leaf; |
| 170 | + }); |
| 171 | + }; |
| 172 | + case (#v0_0_1(v0_0_1)) versions; |
| 173 | + }; |
| 174 | + }; |
| 175 | + |
| 176 | +}; |
0 commit comments