rootfs: convert to BOpenHashTable.

* Add an fs-shell compatible version of BOpenHashTable in the fs_shell
to keep it working. The header is renamed to KOpenHashTable to avoid a
conflict with the OpenHashTable.h available in private/shared which is
not API compatible.
This commit is contained in:
Adrien Destugues 2015-01-13 14:52:01 +01:00
parent 9d053f5975
commit bb3092b298
2 changed files with 544 additions and 47 deletions

View File

@ -8,9 +8,11 @@
#if FS_SHELL
# include <new>
# include "fssh_api_wrapper.h"
# include "hash.h"
# include "KOpenHashTable.h"
# include "list.h"
#else
# include <stdio.h>
@ -23,14 +25,15 @@
# include <NodeMonitor.h>
# include <debug.h>
# include <khash.h>
# include <lock.h>
# include <OpenHashTable.h>
# include <util/AutoLock.h>
# include <vfs.h>
# include <vm/vm.h>
#endif
#if FS_SHELL
using namespace FSShell;
# define user_strlcpy(to, from, len) (strlcpy(to, from, len), FSSH_B_OK)
@ -71,12 +74,39 @@ struct rootfs_vnode {
struct rootfs_stream stream;
};
struct VnodeHash {
typedef ino_t KeyType;
typedef rootfs_vnode ValueType;
size_t HashKey(KeyType key) const
{
return key;
}
size_t Hash(ValueType* vnode) const
{
return vnode->id;
}
bool Compare(KeyType key, ValueType* vnode) const
{
return vnode->id == key;
}
ValueType*& GetLink(ValueType* value) const
{
return value->all_next;
}
};
typedef BOpenHashTable<VnodeHash> VnodeTable;
struct rootfs {
fs_volume* volume;
dev_t id;
rw_lock lock;
ino_t next_vnode_id;
hash_table* vnode_list_hash;
VnodeTable* vnode_list_hash;
struct rootfs_vnode* root_vnode;
};
@ -117,32 +147,6 @@ current_timespec()
}
static uint32
rootfs_vnode_hash_func(void* _v, const void* _key, uint32 range)
{
struct rootfs_vnode* vnode = (rootfs_vnode*)_v;
const ino_t* key = (const ino_t*)_key;
if (vnode != NULL)
return vnode->id % range;
return (uint64)*key % range;
}
static int
rootfs_vnode_compare_func(void* _v, const void* _key)
{
struct rootfs_vnode* v = (rootfs_vnode*)_v;
const ino_t* key = (const ino_t*)_key;
if (v->id == *key)
return 0;
return -1;
}
static struct rootfs_vnode*
rootfs_create_vnode(struct rootfs* fs, struct rootfs_vnode* parent,
const char* name, int type)
@ -188,7 +192,7 @@ rootfs_delete_vnode(struct rootfs* fs, struct rootfs_vnode* v, bool force_delete
return EPERM;
// remove it from the global hash table
hash_remove(fs->vnode_list_hash, v);
fs->vnode_list_hash->Remove(v);
if (S_ISDIR(v->stream.type))
mutex_destroy(&v->stream.dir.cookie_lock);
@ -376,10 +380,9 @@ rootfs_mount(fs_volume* volume, const char* device, uint32 flags,
rw_lock_init(&fs->lock, "rootfs");
fs->vnode_list_hash = hash_init(ROOTFS_HASH_SIZE,
offsetof(rootfs_vnode, all_next), &rootfs_vnode_compare_func,
&rootfs_vnode_hash_func);
if (fs->vnode_list_hash == NULL) {
fs->vnode_list_hash = new(std::nothrow) VnodeTable();
if (fs->vnode_list_hash == NULL
|| fs->vnode_list_hash->Init(ROOTFS_HASH_SIZE) != B_OK) {
err = B_NO_MEMORY;
goto err2;
}
@ -393,7 +396,7 @@ rootfs_mount(fs_volume* volume, const char* device, uint32 flags,
vnode->parent = vnode;
fs->root_vnode = vnode;
hash_insert(fs->vnode_list_hash, vnode);
fs->vnode_list_hash->Insert(vnode);
publish_vnode(volume, vnode->id, vnode, &sVnodeOps, vnode->stream.type, 0);
*_rootID = vnode->id;
@ -401,7 +404,7 @@ rootfs_mount(fs_volume* volume, const char* device, uint32 flags,
return B_OK;
err3:
hash_uninit(fs->vnode_list_hash);
delete fs->vnode_list_hash;
err2:
rw_lock_destroy(&fs->lock);
free(fs);
@ -421,17 +424,14 @@ rootfs_unmount(fs_volume* _volume)
put_vnode(fs->volume, fs->root_vnode->id);
// delete all of the vnodes
struct hash_iterator i;
hash_open(fs->vnode_list_hash, &i);
VnodeTable::Iterator i(fs->vnode_list_hash);
while (struct rootfs_vnode* vnode = (struct rootfs_vnode*)
hash_next(fs->vnode_list_hash, &i)) {
while (i.HasNext()) {
struct rootfs_vnode* vnode = i.Next();
rootfs_delete_vnode(fs, vnode, true);
}
hash_close(fs->vnode_list_hash, &i, false);
hash_uninit(fs->vnode_list_hash);
delete fs->vnode_list_hash;
rw_lock_destroy(&fs->lock);
free(fs);
@ -503,7 +503,7 @@ rootfs_get_vnode(fs_volume* _volume, ino_t id, fs_vnode* _vnode, int* _type,
if (!reenter)
rw_lock_read_lock(&fs->lock);
vnode = (rootfs_vnode*)hash_lookup(fs->vnode_list_hash, &id);
vnode = fs->vnode_list_hash->Lookup(id);
if (!reenter)
rw_lock_read_unlock(&fs->lock);
@ -644,7 +644,7 @@ rootfs_create_dir(fs_volume* _volume, fs_vnode* _dir, const char* name,
return B_NO_MEMORY;
rootfs_insert_in_dir(fs, dir, vnode);
hash_insert(fs->vnode_list_hash, vnode);
fs->vnode_list_hash->Insert(vnode);
entry_cache_add(fs->volume->id, dir->id, name, vnode->id);
notify_entry_created(fs->id, dir->id, name, vnode->id);
@ -877,7 +877,7 @@ rootfs_symlink(fs_volume* _volume, fs_vnode* _dir, const char* name,
return B_NO_MEMORY;
rootfs_insert_in_dir(fs, dir, vnode);
hash_insert(fs->vnode_list_hash, vnode);
fs->vnode_list_hash->Insert(vnode);
vnode->stream.symlink.path = strdup(path);
if (vnode->stream.symlink.path == NULL) {
@ -1086,7 +1086,7 @@ rootfs_create_special_node(fs_volume* _volume, fs_vnode* _dir, const char* name,
else
flags |= B_VNODE_PUBLISH_REMOVED;
hash_insert(fs->vnode_list_hash, vnode);
fs->vnode_list_hash->Insert(vnode);
_superVnode->private_node = vnode;
_superVnode->ops = &sVnodeOps;

View File

@ -0,0 +1,497 @@
/*
* Copyright 2007, Hugo Santos. All Rights Reserved.
* Distributed under the terms of the MIT License.
*/
#ifndef _KERNEL_UTIL_OPEN_HASH_TABLE_H
#define _KERNEL_UTIL_OPEN_HASH_TABLE_H
#include "fssh_api_wrapper.h"
#include <stdlib.h>
#include <string.h>
#ifdef _KERNEL_MODE
# include <KernelExport.h>
# include <util/kernel_cpp.h>
# include <util/TypeOperation.h>
#else
# include <TypeOperation.h>
#endif
/*!
The Definition template must have four methods: `HashKey', `Hash',
`Compare' and `GetLink;. It must also define several types as shown in the
following example:
struct Foo {
int bar;
Foo* fNext;
};
struct HashTableDefinition {
typedef int KeyType;
typedef Foo ValueType;
size_t HashKey(KeyType key) const
{
return key >> 1;
}
size_t Hash(ValueType* value) const
{
return HashKey(value->bar);
}
bool Compare(KeyType key, ValueType* value) const
{
return value->bar == key;
}
ValueType*& GetLink(ValueType* value) const
{
return value->fNext;
}
};
*/
struct MallocAllocator {
void* Allocate(size_t size) const
{
return malloc(size);
}
void Free(void* memory) const
{
free(memory);
}
};
/** Implements an hash table with open hashing, that is, colliding entries are
* stored in a linked list. The table may be made to adjust its number of slots
* depending on the load factor (this should be enabled unless the object is to
* be used at times where memory allocations aren't possible, such as code
* called byt he memory allocator).
*
* The link between entries is part of the ValueType stored items, which makes
* sure the table can always accept new items and will never fail because it is
* out of memory (except at Init time).
*/
template<typename Definition, bool AutoExpand = true,
bool CheckDuplicates = false, typename Allocator = MallocAllocator>
class BOpenHashTable {
public:
typedef BOpenHashTable<Definition, AutoExpand, CheckDuplicates> HashTable;
typedef typename Definition::KeyType KeyType;
typedef typename Definition::ValueType ValueType;
static const size_t kMinimumSize = 8;
// All allocations are of power of 2 lengths.
// regrowth factor: 200 / 256 = 78.125%
// 50 / 256 = 19.53125%
BOpenHashTable()
:
fTableSize(0),
fItemCount(0),
fTable(NULL)
{
}
BOpenHashTable(const Definition& definition)
:
fDefinition(definition),
fTableSize(0),
fItemCount(0),
fTable(NULL)
{
}
BOpenHashTable(const Definition& definition, const Allocator& allocator)
:
fDefinition(definition),
fAllocator(allocator),
fTableSize(0),
fItemCount(0),
fTable(NULL)
{
}
~BOpenHashTable()
{
fAllocator.Free(fTable);
}
status_t Init(size_t initialSize = kMinimumSize)
{
if (initialSize > 0 && !_Resize(initialSize))
return B_NO_MEMORY;
return B_OK;
}
size_t TableSize() const
{
return fTableSize;
}
bool IsEmpty() const
{
return fItemCount == 0;
}
size_t CountElements() const
{
return fItemCount;
}
ValueType* Lookup(typename TypeOperation<KeyType>::ConstRefT key) const
{
if (fTableSize == 0)
return NULL;
size_t index = fDefinition.HashKey(key) & (fTableSize - 1);
ValueType* slot = fTable[index];
while (slot) {
if (fDefinition.Compare(key, slot))
break;
slot = _Link(slot);
}
return slot;
}
status_t Insert(ValueType* value)
{
if (fTableSize == 0) {
if (!_Resize(kMinimumSize))
return B_NO_MEMORY;
} else if (AutoExpand && fItemCount >= (fTableSize * 200 / 256))
_Resize(fTableSize * 2);
InsertUnchecked(value);
return B_OK;
}
/*! \brief Inserts a value without resizing the table.
Use this method if you need to insert a value into the table while
iterating it, as regular insertion can invalidate iterators.
*/
void InsertUnchecked(ValueType* value)
{
if (CheckDuplicates && _ExhaustiveSearch(value)) {
#if defined(_KERNEL_MODE) || defined(FS_SHELL)
panic("Hash Table: value already in table.");
#else
debugger("Hash Table: value already in table.");
#endif
}
_Insert(fTable, fTableSize, value);
fItemCount++;
}
// TODO: a ValueType* Remove(const KeyType& key) method is missing
bool Remove(ValueType* value)
{
if (!RemoveUnchecked(value))
return false;
if (AutoExpand && fTableSize > kMinimumSize
&& fItemCount < (fTableSize * 50 / 256))
_Resize(fTableSize / 2);
return true;
}
/*! \brief Removes a value without resizing the table.
Use this method if you need to remove a value from the table while
iterating it, as Remove can invalidate iterators.
Also use this method if you know you are going to reinsert the item soon
(possibly with a different hash) to avoid shrinking then growing the
table again.
*/
bool RemoveUnchecked(ValueType* value)
{
size_t index = fDefinition.Hash(value) & (fTableSize - 1);
ValueType* previous = NULL;
ValueType* slot = fTable[index];
while (slot) {
ValueType* next = _Link(slot);
if (value == slot) {
if (previous)
_Link(previous) = next;
else
fTable[index] = next;
break;
}
previous = slot;
slot = next;
}
if (slot == NULL)
return false;
if (CheckDuplicates && _ExhaustiveSearch(value)) {
#if defined(_KERNEL_MODE) || defined(FS_SHELL)
panic("Hash Table: duplicate detected.");
#else
debugger("Hash Table: duplicate detected.");
#endif
}
fItemCount--;
return true;
}
/*! \brief Removes all elements from the hash table.
No resizing happens. The elements are not deleted. If \a returnElements
is \c true, the method returns all elements chained via their hash table
link.
*/
ValueType* Clear(bool returnElements = false)
{
if (fItemCount == 0)
return NULL;
ValueType* result = NULL;
if (returnElements) {
ValueType** nextPointer = &result;
// iterate through all buckets
for (size_t i = 0; i < fTableSize; i++) {
ValueType* element = fTable[i];
if (element != NULL) {
// add the bucket to the list
*nextPointer = element;
// update nextPointer to point to the fNext of the last
// element in the bucket
while (element != NULL) {
nextPointer = &_Link(element);
element = *nextPointer;
}
}
}
}
memset(this->fTable, 0, sizeof(ValueType*) * this->fTableSize);
fItemCount = 0;
return result;
}
/*! If the table needs resizing, the number of bytes for the required
allocation is returned. If no resizing is needed, 0 is returned.
*/
size_t ResizeNeeded() const
{
size_t size = fTableSize;
if (size == 0 || fItemCount >= (size * 200 / 256)) {
// grow table
if (size == 0)
size = kMinimumSize;
while (fItemCount >= size * 200 / 256)
size <<= 1;
} else if (size > kMinimumSize && fItemCount < size * 50 / 256) {
// shrink table
while (fItemCount < size * 50 / 256)
size >>= 1;
if (size < kMinimumSize)
size = kMinimumSize;
}
if (size == fTableSize)
return 0;
return size * sizeof(ValueType*);
}
/*! Resizes the table using the given allocation. The allocation must not
be \c NULL. It must be of size \a size, which must be a value returned
earlier by ResizeNeeded(). If the size requirements have changed in the
meantime, the method free()s the given allocation and returns \c false,
unless \a force is \c true, in which case the supplied allocation is
used in any event.
Otherwise \c true is returned.
If \a oldTable is non-null and resizing is successful, the old table
will not be freed, but will be returned via this parameter instead.
*/
bool Resize(void* allocation, size_t size, bool force = false,
void** oldTable = NULL)
{
if (!force && size != ResizeNeeded()) {
fAllocator.Free(allocation);
return false;
}
_Resize((ValueType**)allocation, size / sizeof(ValueType*), oldTable);
return true;
}
/*! \brief Iterator for BOpenHashMap
The iterator is not invalidated when removing the current element from
the table, unless the removal triggers a resize.
*/
class Iterator {
public:
Iterator(const HashTable* table)
: fTable(table)
{
Rewind();
}
Iterator(const HashTable* table, size_t index, ValueType* value)
: fTable(table), fIndex(index), fNext(value) {}
bool HasNext() const { return fNext != NULL; }
ValueType* Next()
{
ValueType* current = fNext;
_GetNext();
return current;
}
void Rewind()
{
// get the first one
fIndex = 0;
fNext = NULL;
_GetNext();
}
protected:
Iterator() {}
void _GetNext()
{
if (fNext)
fNext = fTable->_Link(fNext);
while (fNext == NULL && fIndex < fTable->fTableSize)
fNext = fTable->fTable[fIndex++];
}
const HashTable* fTable;
size_t fIndex;
ValueType* fNext;
};
Iterator GetIterator() const
{
return Iterator(this);
}
Iterator GetIterator(typename TypeOperation<KeyType>::ConstRefT key) const
{
if (fTableSize == 0)
return Iterator(this, fTableSize, NULL);
size_t index = fDefinition.HashKey(key) & (fTableSize - 1);
ValueType* slot = fTable[index];
while (slot) {
if (fDefinition.Compare(key, slot))
break;
slot = _Link(slot);
}
if (slot == NULL)
return Iterator(this, fTableSize, NULL);
return Iterator(this, index + 1, slot);
}
protected:
// for g++ 2.95
friend class Iterator;
void _Insert(ValueType** table, size_t tableSize, ValueType* value)
{
size_t index = fDefinition.Hash(value) & (tableSize - 1);
_Link(value) = table[index];
table[index] = value;
}
bool _Resize(size_t newSize)
{
ValueType** newTable
= (ValueType**)fAllocator.Allocate(sizeof(ValueType*) * newSize);
if (newTable == NULL)
return false;
_Resize(newTable, newSize);
return true;
}
void _Resize(ValueType** newTable, size_t newSize, void** _oldTable = NULL)
{
for (size_t i = 0; i < newSize; i++)
newTable[i] = NULL;
if (fTable) {
for (size_t i = 0; i < fTableSize; i++) {
ValueType* bucket = fTable[i];
while (bucket) {
ValueType* next = _Link(bucket);
_Insert(newTable, newSize, bucket);
bucket = next;
}
}
if (_oldTable != NULL)
*_oldTable = fTable;
else
fAllocator.Free(fTable);
} else if (_oldTable != NULL)
*_oldTable = NULL;
fTableSize = newSize;
fTable = newTable;
}
ValueType*& _Link(ValueType* bucket) const
{
return fDefinition.GetLink(bucket);
}
bool _ExhaustiveSearch(ValueType* value) const
{
for (size_t i = 0; i < fTableSize; i++) {
ValueType* bucket = fTable[i];
while (bucket) {
if (bucket == value)
return true;
bucket = _Link(bucket);
}
}
return false;
}
Definition fDefinition;
Allocator fAllocator;
size_t fTableSize;
size_t fItemCount;
ValueType** fTable;
};
#endif // _KERNEL_UTIL_OPEN_HASH_TABLE_H