Moved LRU to its own file

This commit is contained in:
ridiculousfish 2012-02-05 20:54:41 -08:00
parent 5ad6849d4e
commit 9ab54030b9
6 changed files with 355 additions and 315 deletions

View file

@ -7,6 +7,8 @@
objects = {
/* Begin PBXFileReference section */
D03EE83714DF88B200FC7150 /* lru.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = lru.cpp; sourceTree = "<group>"; };
D03EE83814DF88B200FC7150 /* lru.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = lru.h; sourceTree = "<group>"; };
D049018814B3802E003CEFBC /* builtin_scripts.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = builtin_scripts.cpp; sourceTree = "<group>"; };
D049018914B3802E003CEFBC /* builtin_scripts.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = builtin_scripts.h; sourceTree = "<group>"; };
D0A0850313B3ACEE0099B651 /* builtin.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = builtin.h; sourceTree = "<group>"; };
@ -176,6 +178,8 @@
D0A0851813B3ACEE0099B651 /* kill.h */,
D0A0854F13B3ACEE0099B651 /* kill.cpp */,
D0A0854E13B3ACEE0099B651 /* key_reader.cpp */,
D03EE83814DF88B200FC7150 /* lru.h */,
D03EE83714DF88B200FC7150 /* lru.cpp */,
D0A0851913B3ACEE0099B651 /* mimedb.h */,
D0A0855013B3ACEE0099B651 /* mimedb.cpp */,
D0A0851A13B3ACEE0099B651 /* output.h */,

View file

@ -37,125 +37,6 @@ file_access_attempt_t access_file(const wcstring &path, int mode) {
return result;
}
lru_cache_impl_t::lru_cache_impl_t(size_t size) : max_node_count(size), node_count(0), mouth(L"") {
/* Hook up the mouth to itself: a one node circularly linked list */
mouth.prev = mouth.next = &mouth;
}
void lru_cache_impl_t::node_was_evicted(lru_node_t *node) { }
void lru_cache_impl_t::evict_node(lru_node_t *condemned_node) {
/* We should never evict the mouth */
assert(condemned_node != NULL && condemned_node != &mouth);
/* Remove it from the linked list */
condemned_node->prev->next = condemned_node->next;
condemned_node->next->prev = condemned_node->prev;
/* Remove us from the set */
node_set.erase(condemned_node);
node_count--;
/* Tell ourselves */
this->node_was_evicted(condemned_node);
}
void lru_cache_impl_t::evict_last_node(void) {
/* Simple */
evict_node(mouth.prev);
}
bool lru_cache_impl_t::evict_node(const wcstring &key) {
/* Construct a fake node as our key */
lru_node_t node_key(key);
/* Look for it in the set */
node_set_t::iterator iter = node_set.find(&node_key);
if (iter == node_set.end())
return false;
/* Evict the given node */
evict_node(*iter);
return true;
}
void lru_cache_impl_t::promote_node(lru_node_t *node) {
/* We should never promote the mouth */
assert(node != &mouth);
/* First unhook us */
node->prev->next = node->next;
node->next->prev = node->prev;
/* Put us after the mouth */
node->next = mouth.next;
node->next->prev = node;
node->prev = &mouth;
mouth.next = node;
}
bool lru_cache_impl_t::add_node(lru_node_t *node) {
/* Add our node without eviction */
if (! this->add_node_without_eviction(node))
return false;
/* Evict */
while (node_count > max_node_count)
evict_last_node();
/* Success */
return true;
}
bool lru_cache_impl_t::add_node_without_eviction(lru_node_t *node) {
assert(node != NULL && node != &mouth);
/* Try inserting; return false if it was already in the set */
if (! node_set.insert(node).second)
return false;
/* Add the node after the mouth */
node->next = mouth.next;
node->next->prev = node;
node->prev = &mouth;
mouth.next = node;
/* Update the count */
node_count++;
/* Evict */
while (node_count > max_node_count)
evict_last_node();
/* Success */
return true;
}
lru_node_t *lru_cache_impl_t::get_node(const wcstring &key) {
lru_node_t *result = NULL;
/* Construct a fake node as our key */
lru_node_t node_key(key);
/* Look for it in the set */
node_set_t::iterator iter = node_set.find(&node_key);
/* If we found a node, promote and return it */
if (iter != node_set.end()) {
result = *iter;
promote_node(result);
}
return result;
}
void lru_cache_impl_t::evict_all_nodes() {
while (node_count > 0) {
evict_last_node();
}
}
autoload_t::autoload_t(const wcstring &env_var_name_var, const builtin_script_t * const scripts, size_t script_count) :
env_var_name(env_var_name_var),
builtin_scripts(scripts),

View file

@ -11,6 +11,7 @@
#include <set>
#include <list>
#include "common.h"
#include "lru.h"
/** A struct responsible for recording an attempt to access a file. */
struct file_access_attempt_t {
@ -21,83 +22,8 @@ struct file_access_attempt_t {
int error; /** If we could not access the file, the error code */
};
/** A predicate to compare dereferenced pointers */
struct dereference_less_t {
template <typename ptr_t>
bool operator()(ptr_t p1, ptr_t p2) const { return *p1 < *p2; }
};
file_access_attempt_t access_file(const wcstring &path, int mode);
class lru_node_t {
friend class lru_cache_impl_t;
/** Our linked list pointer */
lru_node_t *prev, *next;
public:
/** The key used to look up in the cache */
const wcstring key;
/** Constructor */
lru_node_t(const wcstring &keyVar) : prev(NULL), next(NULL), key(keyVar) { }
bool operator<(const lru_node_t &other) const { return key < other.key; }
};
class lru_cache_impl_t {
private:
void promote_node(lru_node_t *);
void evict_node(lru_node_t *node);
void evict_last_node(void);
/** Max node count */
const size_t max_node_count;
/** Count of nodes */
size_t node_count;
/** The set of nodes */
typedef std::set<lru_node_t *, dereference_less_t> node_set_t;
node_set_t node_set;
/** Head of the linked list */
lru_node_t mouth;
protected:
/** Overridable callback for when a node is evicted */
virtual void node_was_evicted(lru_node_t *node);
public:
/** Constructor */
lru_cache_impl_t(size_t max_size = 1024 );
/** Returns the node for a given key, or NULL */
lru_node_t *get_node(const wcstring &key);
/** Evicts the node for a given key, returning true if a node was evicted. */
bool evict_node(const wcstring &key);
/** Adds a node under the given key. Returns true if the node was added, false if the node was not because a node with that key is already in the set. */
bool add_node(lru_node_t *node);
/** Adds a node under the given key without triggering eviction. Returns true if the node was added, false if the node was not because a node with that key is already in the set. */
bool add_node_without_eviction(lru_node_t *node);
/** Counts nodes */
size_t size(void) { return node_count; }
/** Evicts all nodes */
void evict_all_nodes(void);
};
/** Template cover to avoid casting */
template<class node_type_t>
class lru_cache_t : public lru_cache_impl_t {
public:
node_type_t *get_node(const wcstring &key) { return static_cast<node_type_t *>(lru_cache_impl_t::get_node(key)); }
bool add_node(node_type_t *node) { return lru_cache_impl_t::add_node(node); }
lru_cache_t(size_t max_size = 1024 ) : lru_cache_impl_t(max_size) { }
};
struct autoload_function_t : public lru_node_t
{
autoload_function_t(const wcstring &key) : lru_node_t(key), is_loaded(false), is_placeholder(false) { bzero(&access, sizeof access); }

View file

@ -28,7 +28,55 @@
#include "intern.h"
#include "path.h"
#include "signal.h"
#include "autoload.h"
#include <map>
#include <algorithm>
/** When we rewrite the history, the number of items we keep */
#define HISTORY_SAVE_MAX (1024 * 256)
/** Interval in seconds between automatic history save */
#define SAVE_INTERVAL (5*60)
/** Number of new history entries to add before automatic history save */
#define SAVE_COUNT 5
/* Our LRU cache is used for restricting the amount of history we have, and limiting how long we order it. */
class history_lru_node_t : public lru_node_t {
public:
time_t timestamp;
history_lru_node_t(const history_item_t &item) : lru_node_t(item.str()), timestamp(item.timestamp())
{
}
};
class history_lru_cache_t : public lru_cache_t<history_lru_node_t> {
protected:
/* Override to delete evicted nodes */
virtual void node_was_evicted(history_lru_node_t *node) {
delete node;
}
public:
history_lru_cache_t(size_t max) : lru_cache_t<history_lru_node_t>(max) { }
/* Function to add a history item */
void add_item(const history_item_t &item) {
/* Skip empty items */
if (item.empty())
return;
/* See if it's in the cache. If it is, update the timestamp. If not, we create a new node and add it. Note that calling get_node promotes the node to the front. */
history_lru_node_t *node = this->get_node(item.str());
if (node != NULL) {
node->timestamp = std::max(node->timestamp, item.timestamp());
} else {
node = new history_lru_node_t(item);
this->add_node(node);
}
}
};
static pthread_mutex_t hist_lock = PTHREAD_MUTEX_INITIALIZER;
@ -36,11 +84,12 @@ static std::map<wcstring, history_t *> histories;
static wcstring history_filename(const wcstring &name, const wcstring &suffix);
static hash_table_t *mode_table=0;
/* Unescapes newlines in-place */
static void unescape_newlines(wcstring &str);
/* Escapes newlines in-place */
static void escape_newlines(wcstring &str);
/* Custom deleter for our shared_ptr */
class history_item_data_deleter_t {
private:
@ -53,15 +102,19 @@ class history_item_data_deleter_t {
}
};
history_item_t::history_item_t(const wcstring &str) : contents(str), timestamp(time(NULL))
history_item_t::history_item_t(const wcstring &str) : contents(str), creation_timestamp(time(NULL))
{
}
history_item_t::history_item_t(const wcstring &str, time_t when) : contents(str), timestamp(when)
history_item_t::history_item_t(const wcstring &str, time_t when) : contents(str), creation_timestamp(when)
{
}
bool history_item_t::write_to_file(FILE *f) const {
wcstring escaped = contents;
escape_newlines(escaped);
return fwprintf( f, L"# %d\n%ls\n", creation_timestamp, escaped.c_str());
}
history_t & history_t::history_with_name(const wcstring &name) {
/* Note that histories are currently never deleted, so we can return a reference to them without using something like shared_ptr */
@ -91,6 +144,10 @@ void history_t::add(const wcstring &str)
{
scoped_lock locker(lock);
new_items.push_back(history_item_t(str.c_str(), true));
/* This might be a good candidate for moving to a background thread */
if((time(0) > save_timestamp + SAVE_INTERVAL) || (new_items.size() >= SAVE_COUNT))
this->save_internal();
}
history_item_t history_t::item_at_index(size_t idx) {
@ -350,15 +407,6 @@ history_item_t history_search_t::current_item() const {
return history->item_at_index(idx);
}
/**
Interval in seconds between automatic history save
*/
#define SAVE_INTERVAL (5*60)
/**
Number of new history entries to add before automatic history save
*/
#define SAVE_COUNT 5
/**
A struct representiong a history list
@ -529,10 +577,8 @@ static wchar_t *history_escape_newlines( wchar_t *in )
return (wchar_t *)out->buff;
}
static void unescape_newlines(wcstring &str)
static void replace_all(wcstring &str, const wchar_t *needle, const wchar_t *replacement)
{
/* Replace instances of backslash + newline with just the newline */
const wchar_t *needle = L"\\\n", *replacement = L"\n";
size_t needle_len = wcslen(needle);
size_t offset = 0;
while((offset = str.find(needle, offset)) != wcstring::npos)
@ -542,6 +588,22 @@ static void unescape_newlines(wcstring &str)
}
}
static void unescape_newlines(wcstring &str)
{
/* Replace instances of backslash + newline with just the newline */
replace_all(str, L"\\\n", L"\n");
}
static void escape_newlines(wcstring &str)
{
/* Replace instances of newline with backslash + newline with newline */
replace_all(str, L"\\\n", L"\n");
/* If the string ends with a backslash, we'll combine it with the next line. Hack around that by appending a newline. */
if (! str.empty() && str.at(str.size() - 1) == L'\\')
str.push_back('\n');
}
/**
Remove backslashes from all newlines. This makes a string from the
history file better formated for on screen display. The memory for
@ -949,83 +1011,55 @@ static void history_load( history_mode_t *m )
signal_unblock();
}
#if 0
/**
Save the specified mode to file
*/
void history_t::save( void *n, history_mode_t *m )
/** Save the specified mode to file */
void history_t::save_internal()
{
scoped_lock locker(lock);
/* This must be called while locked */
/* Nothing to do if there's no new items */
if (new_items.empty())
return;
FILE *out;
int i;
int has_new=0;
wchar_t *tmp_name;
int ok = 1;
bool ok = true;
signal_block();
wcstring tmp_name = history_filename(name, L".tmp");
if( ! tmp_name.empty() )
{
if( (out=wfopen( tmp_name, "w" ) ) )
FILE *out;
if( (out=wfopen( tmp_name.c_str(), "w" ) ) )
{
hash_table_t mine;
hash_init( &mine, &hash_item_func, &hash_item_cmp );
for( i=0; i<al_get_count(&m->item); i++ )
{
void *ptr = al_get( &m->item, i );
int is_new = item_is_new( m, ptr );
if( is_new )
{
hash_put( &mine, item_get( m, ptr ), L"" );
}
}
/*
Re-save the old history
*/
for( i=0; ok && (i<al_get_count(&on_disk->item)); i++ )
{
void *ptr = al_get( &on_disk->item, i );
item_t *i = item_get( on_disk, ptr );
if( !hash_get( &mine, i ) )
{
if( item_write( out, on_disk, ptr ) == -1 )
{
ok = 0;
break;
}
}
}
hash_destroy( &mine );
/*
Add our own items last
*/
for( i=0; ok && (i<al_get_count(&m->item)); i++ )
{
void *ptr = al_get( &m->item, i );
int is_new = item_is_new( m, ptr );
if( is_new )
{
if( item_write( out, m, ptr ) == -1 )
{
ok = 0;
}
}
}
/* Load old */
load_old_if_needed();
/* Make an LRU cache to save only the last N elements */
history_lru_cache_t lru(HISTORY_SAVE_MAX);
/* Insert old items in, from old to new */
for (std::vector<size_t>::iterator iter = old_item_offsets.begin(); iter != old_item_offsets.end(); iter++) {
size_t offset = *iter;
history_item_t item = history_t::decode_item(mmap_start + offset, mmap_length - offset);
lru.add_item(item);
}
/* Insert new items */
for (std::vector<history_item_t>::iterator iter = new_items.begin(); iter != new_items.end(); iter++) {
lru.add_item(*iter);
}
/* Write them out */
for (history_lru_cache_t::iterator iter = lru.begin(); iter != lru.end(); iter++) {
#if 0
if (! (*iter)->write_to_file(out)) {
ok = false;
break;
}
#endif
}
if( fclose( out ) || !ok )
{
/*
@ -1036,43 +1070,33 @@ void history_t::save( void *n, history_mode_t *m )
}
else
{
wrename( tmp_name, history_filename( on_disk, m->name, 0 ) );
wcstring new_name = history_filename(name, wcstring());
wrename(tmp_name.c_str(), new_name.c_str());
}
}
free( tmp_name );
}
halloc_free( on_disk);
if( ok )
{
/*
Reset the history. The item_t entries created in this session
are not lost or dropped, they are stored in the session_item
hash table. On reload, they will be automatically inserted at
the end of the history list.
*/
if( m->mmap_start && (m->mmap_start != MAP_FAILED ) )
{
munmap( m->mmap_start, m->mmap_length );
}
al_truncate( &m->item, 0 );
al_truncate( &m->used, 0 );
m->pos = 0;
m->has_loaded = 0;
m->mmap_start=0;
m->mmap_length=0;
m->save_timestamp=time(0);
m->new_count = 0;
/* Our history has been written to the file, so clear our state so we can re-reference the file. */
if (mmap_start != NULL && mmap_start != MAP_FAILED) {
munmap((void *)mmap_start, mmap_length);
}
mmap_start = 0;
mmap_length = 0;
loaded_old = false;
new_items.clear();
old_item_offsets.clear();
save_timestamp=time(0);
}
signal_unblock();
}
#endif
void history_t::save(void) {
scoped_lock locker(lock);
this->save_internal();
}
/**
Save the specified mode to file
@ -1425,14 +1449,10 @@ void history_init()
void history_destroy()
{
if( mode_table )
{
hash_foreach( mode_table, (void (*)(void *, void *))&history_save_mode );
hash_foreach( mode_table, (void (*)(void *, void *))&history_destroy_mode_wrapper );
hash_destroy( mode_table );
free( mode_table );
mode_table=0;
}
/* Save all histories */
for (std::map<wcstring, history_t *>::iterator iter = histories.begin(); iter != histories.end(); iter++) {
iter->second->save();
}
}

View file

@ -23,12 +23,15 @@ class history_item_t {
wcstring contents;
/** Original creation time for the entry */
time_t timestamp;
time_t creation_timestamp;
public:
const wcstring &str() const { return contents; }
bool empty() const { return contents.empty(); }
bool matches_search(const wcstring &val) const { return contents.find(val) != wcstring::npos; }
time_t timestamp() const { return creation_timestamp; }
bool write_to_file(FILE *f) const;
};
class history_t {
@ -76,6 +79,9 @@ private:
/** Loads old if necessary */
void load_old_if_needed(void);
/** Saves history */
void save_internal();
public:
/** Returns history with the given name, creating it if necessary */
static history_t & history_with_name(const wcstring &name);
@ -123,16 +129,14 @@ public:
history(&hist),
term(str),
idx()
{
}
{}
/* Default constructor */
history_search_t() :
history(),
term(),
idx()
{
}
{}
};

205
lru.h Normal file
View file

@ -0,0 +1,205 @@
/** \file lru.h
Least-recently-used cache implementation
*/
#ifndef FISH_LRU_H
#define FISH_LRU_H
#include <wchar.h>
#include <map>
#include <set>
#include <list>
#include "common.h"
/** A predicate to compare dereferenced pointers */
struct dereference_less_t {
template <typename ptr_t>
bool operator()(ptr_t p1, ptr_t p2) const { return *p1 < *p2; }
};
class lru_node_t {
template<class T> friend class lru_cache_t;
/** Our linked list pointer */
lru_node_t *prev, *next;
public:
/** The key used to look up in the cache */
const wcstring key;
/** Constructor */
lru_node_t(const wcstring &pkey) : prev(NULL), next(NULL), key(pkey) { }
/** operator< for std::set */
bool operator<(const lru_node_t &other) const { return key < other.key; }
};
template<class node_type_t>
class lru_cache_t {
private:
/** Max node count */
const size_t max_node_count;
/** Count of nodes */
size_t node_count;
/** The set of nodes */
typedef std::set<lru_node_t *, dereference_less_t> node_set_t;
node_set_t node_set;
void promote_node(node_type_t *node) {
/* We should never promote the mouth */
assert(node != &mouth);
/* First unhook us */
node->prev->next = node->next;
node->next->prev = node->prev;
/* Put us after the mouth */
node->next = mouth.next;
node->next->prev = node;
node->prev = &mouth;
mouth.next = node;
}
void evict_node(node_type_t *condemned_node) {
/* We should never evict the mouth */
assert(condemned_node != NULL && condemned_node != &mouth);
/* Remove it from the linked list */
condemned_node->prev->next = condemned_node->next;
condemned_node->next->prev = condemned_node->prev;
/* Remove us from the set */
node_set.erase(condemned_node);
node_count--;
/* Tell ourselves */
this->node_was_evicted(condemned_node);
}
void evict_last_node(void) {
/* Simple */
evict_node((node_type_t *)mouth.prev);
}
protected:
/** Head of the linked list */
lru_node_t mouth;
/** Overridable callback for when a node is evicted */
virtual void node_was_evicted(node_type_t *node) { }
public:
/** Constructor */
lru_cache_t(size_t max_size = 1024 ) : max_node_count(max_size), node_count(0), mouth(wcstring()) {
/* Hook up the mouth to itself: a one node circularly linked list! */
mouth.prev = mouth.next = &mouth;
}
/** Returns the node for a given key, or NULL */
node_type_t *get_node(const wcstring &key) {
node_type_t *result = NULL;
/* Construct a fake node as our key */
lru_node_t node_key(key);
/* Look for it in the set */
node_set_t::iterator iter = node_set.find(&node_key);
/* If we found a node, promote and return it */
if (iter != node_set.end()) {
result = static_cast<node_type_t*>(*iter);
promote_node(result);
}
return result;
}
/** Evicts the node for a given key, returning true if a node was evicted. */
bool evict_node(const wcstring &key) {
/* Construct a fake node as our key */
lru_node_t node_key(key);
/* Look for it in the set */
node_set_t::iterator iter = node_set.find(&node_key);
if (iter == node_set.end())
return false;
/* Evict the given node */
evict_node(static_cast<node_type_t*>(*iter));
return true;
}
/** Adds a node under the given key. Returns true if the node was added, false if the node was not because a node with that key is already in the set. */
bool add_node(node_type_t *node) {
/* Add our node without eviction */
if (! this->add_node_without_eviction(node))
return false;
/* Evict */
while (node_count > max_node_count)
evict_last_node();
/* Success */
return true;
}
/** Adds a node under the given key without triggering eviction. Returns true if the node was added, false if the node was not because a node with that key is already in the set. */
bool add_node_without_eviction(node_type_t *node) {
assert(node != NULL && node != &mouth);
/* Try inserting; return false if it was already in the set */
if (! node_set.insert(node).second)
return false;
/* Add the node after the mouth */
node->next = mouth.next;
node->next->prev = node;
node->prev = &mouth;
mouth.next = node;
/* Update the count */
node_count++;
/* Evict */
while (node_count > max_node_count)
evict_last_node();
/* Success */
return true;
}
/** Counts nodes */
size_t size(void) {
return node_count;
}
/** Evicts all nodes */
void evict_all_nodes(void) {
while (node_count > 0) {
evict_last_node();
}
}
/** Iterator for walking nodes, from least recently used to most */
class iterator {
lru_node_t *node;
public:
iterator(lru_node_t *val) : node(val) { }
void operator++() { node = node->prev; }
void operator++(int x) { node = node->prev; }
bool operator==(const iterator &other) { return node == other.node; }
bool operator!=(const iterator &other) { return !(*this == other); }
node_type_t *operator*() { return static_cast<node_type_t *>(node); }
};
iterator begin() { return iterator(mouth.prev); }
iterator end() { return iterator(&mouth); }
};
#endif