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foxbox/firmware/common/dircache.c
Thomas Martitz d0b72e2590 GSoC/Buflib: Add buflib memory alocator to the core. 
The buflib memory allocator is handle based and can free and
compact, move or resize memory on demand. This allows to effeciently
allocate memory dynamically without an MMU, by avoiding fragmentation
through memory compaction.

This patch adds the buflib library to the core, along with
convinience wrappers to omit the context parameter. Compaction is
not yet enabled, but will be in a later patch. Therefore, this acts as a
replacement for buffer_alloc/buffer_get_buffer() with the benifit of a debug
menu.

See buflib.h for some API documentation.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30380 a1c6a512-1295-4272-9138-f99709370657
2011-08-30 14:01:33 +00:00

1538 lines
40 KiB
C
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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2005 by Miika Pekkarinen
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
/* TODO:
- Allow cache live updating while transparent rebuild is running.
*/
#include "config.h"
#include <stdio.h>
#include <errno.h>
#include "string-extra.h"
#include <stdbool.h>
#include <stdlib.h>
#include "debug.h"
#include "system.h"
#include "logf.h"
#include "dircache.h"
#include "thread.h"
#include "kernel.h"
#include "usb.h"
#include "file.h"
#include "core_alloc.h"
#include "dir.h"
#include "storage.h"
#if CONFIG_RTC
#include "time.h"
#include "timefuncs.h"
#endif
#include "rbpaths.h"
/* Queue commands. */
#define DIRCACHE_BUILD 1
#define DIRCACHE_STOP 2
#if (MEMORYSIZE > 8)
#define MAX_OPEN_DIRS 12
#else
#define MAX_OPEN_DIRS 8
#endif
static DIR_CACHED opendirs[MAX_OPEN_DIRS];
static char opendir_dnames[MAX_OPEN_DIRS][MAX_PATH];
#define MAX_PENDING_BINDINGS 2
struct fdbind_queue {
char path[MAX_PATH];
int fd;
};
/* Exported structures. */
struct dircache_entry {
struct dirinfo info;
struct dircache_entry *next;
struct dircache_entry *up;
struct dircache_entry *down;
long startcluster;
char *d_name;
};
/* Cache Layout:
*
* x - array of struct dircache_entry
* r - reserved buffer
* d - name buffer for the d_name entry of the struct dircache_entry
* |xxxxxx|rrrrrrrrr|dddddd|
*
* subsequent x are allocated from the front, d are allocated from the back,
* using the reserve buffer for entries added after initial scan
*
* after a while the cache may look like:
* |xxxxxxxx|rrrrr|dddddddd|
*
* after a reboot, the reserve buffer is restored in it's size, so that the
* total allocation size grows
* |xxxxxxxx|rrrrrrrrr|dddddddd|
*/
/* this points to the beginnging of the buffer and the first entry */
static struct dircache_entry *dircache_root;
/* these point to the start and end of the name buffer (d above) */
static char *d_names_start, *d_names_end;
/* put "." and ".." into the d_names buffer to enable easy pointer logic */
static char *dot, *dotdot;
#ifdef HAVE_MULTIVOLUME
static struct dircache_entry *append_position;
#endif
static DIR_CACHED opendirs[MAX_OPEN_DIRS];
static struct dircache_entry *fd_bindings[MAX_OPEN_FILES];
static bool dircache_initialized = false;
static bool dircache_initializing = false;
static bool thread_enabled = false;
static unsigned long allocated_size = 0;
static unsigned long dircache_size = 0;
static unsigned long entry_count = 0;
static unsigned long reserve_used = 0;
static unsigned int cache_build_ticks = 0;
static unsigned long appflags = 0;
static struct event_queue dircache_queue SHAREDBSS_ATTR;
static long dircache_stack[(DEFAULT_STACK_SIZE + 0x400)/sizeof(long)];
static const char dircache_thread_name[] = "dircache";
static struct fdbind_queue fdbind_cache[MAX_PENDING_BINDINGS];
static int fdbind_idx = 0;
/* --- Internal cache structure control functions --- */
static inline struct dircache_entry* get_entry(int id)
{
return &dircache_root[id];
}
#ifdef HAVE_EEPROM_SETTINGS
/**
* Open the dircache file to save a snapshot on disk
*/
static int open_dircache_file(unsigned flags, int permissions)
{
if (permissions != 0)
return open(DIRCACHE_FILE, flags, permissions);
return open(DIRCACHE_FILE, flags);
}
/**
* Remove the snapshot file
*/
static int remove_dircache_file(void)
{
return remove(DIRCACHE_FILE);
}
#endif
/**
* Internal function to allocate a new dircache_entry from memory.
*/
static struct dircache_entry* allocate_entry(void)
{
struct dircache_entry *next_entry;
if (dircache_size > allocated_size - MAX_PATH*2)
{
logf("size limit reached");
return NULL;
}
next_entry = &dircache_root[entry_count++];
next_entry->d_name = NULL;
next_entry->up = NULL;
next_entry->down = NULL;
next_entry->next = NULL;
dircache_size += sizeof(struct dircache_entry);
return next_entry;
}
/**
* Internal function to allocate a dircache_entry and set
* ->next entry pointers.
*/
static struct dircache_entry* dircache_gen_next(struct dircache_entry *ce)
{
struct dircache_entry *next_entry;
if ( (next_entry = allocate_entry()) == NULL)
return NULL;
next_entry->up = ce->up;
ce->next = next_entry;
return next_entry;
}
/*
* Internal function to allocate a dircache_entry and set
* ->down entry pointers.
*/
static struct dircache_entry* dircache_gen_down(struct dircache_entry *ce)
{
struct dircache_entry *next_entry;
if ( (next_entry = allocate_entry()) == NULL)
return NULL;
next_entry->up = ce;
ce->down = next_entry;
return next_entry;
}
/**
* Returns true if there is an event waiting in the queue
* that requires the current operation to be aborted.
*/
static bool check_event_queue(void)
{
struct queue_event ev;
if(!queue_peek(&dircache_queue, &ev))
return false;
switch (ev.id)
{
case DIRCACHE_STOP:
case SYS_USB_CONNECTED:
#ifdef HAVE_HOTSWAP
case SYS_FS_CHANGED:
#endif
return true;
}
return false;
}
#if (CONFIG_PLATFORM & PLATFORM_NATIVE)
/* scan and build static data (avoid redundancy on stack) */
static struct
{
#ifdef HAVE_MULTIVOLUME
int volume;
#endif
struct fat_dir *dir;
struct fat_direntry *direntry;
}sab;
static int sab_process_dir(unsigned long startcluster, struct dircache_entry *ce)
{
/* normally, opendir expects a full fat_dir as parent but in our case,
* it's completely useless because we don't modify anything
* WARNING: this heavily relies on current FAT implementation ! */
/* those field are necessary to update the FAT entry in case of modification
here we don't touch anything so we put dummy values */
sab.dir->entry = 0;
sab.dir->entrycount = 0;
sab.dir->file.firstcluster = 0;
/* open directory */
int rc = fat_opendir(IF_MV2(sab.volume,) sab.dir, startcluster, sab.dir);
if(rc < 0)
{
logf("fat_opendir failed: %d", rc);
return rc;
}
/* first pass : read dir */
struct dircache_entry *first_ce = ce;
/* read through directory */
while((rc = fat_getnext(sab.dir, sab.direntry)) >= 0 && sab.direntry->name[0])
{
if(!strcmp(".", sab.direntry->name) ||
!strcmp("..", sab.direntry->name))
continue;
size_t size = strlen(sab.direntry->name) + 1;
ce->d_name = (d_names_start -= size);
ce->startcluster = sab.direntry->firstcluster;
ce->info.size = sab.direntry->filesize;
ce->info.attribute = sab.direntry->attr;
ce->info.wrtdate = sab.direntry->wrtdate;
ce->info.wrttime = sab.direntry->wrttime;
strcpy(ce->d_name, sab.direntry->name);
dircache_size += size;
if(ce->info.attribute & FAT_ATTR_DIRECTORY)
dircache_gen_down(ce);
ce = dircache_gen_next(ce);
if(ce == NULL)
return -5;
/* When simulator is used, it's only safe to yield here. */
if(thread_enabled)
{
/* Stop if we got an external signal. */
if(check_event_queue())
return -6;
yield();
}
}
/* add "." and ".." */
ce->d_name = dot;
ce->info.attribute = FAT_ATTR_DIRECTORY;
ce->startcluster = startcluster;
ce->info.size = 0;
ce->down = first_ce;
ce = dircache_gen_next(ce);
ce->d_name = dotdot;
ce->info.attribute = FAT_ATTR_DIRECTORY;
ce->startcluster = (first_ce->up ? first_ce->up->startcluster : 0);
ce->info.size = 0;
ce->down = first_ce->up;
/* second pass: recurse ! */
ce = first_ce;
while(rc >= 0 && ce)
{
if(ce->d_name != NULL && ce->down != NULL && strcmp(ce->d_name, ".")
&& strcmp(ce->d_name, ".."))
rc = sab_process_dir(ce->startcluster, ce->down);
ce = ce->next;
}
return rc;
}
/* used during the generation */
static struct fat_dir sab_fat_dir;
static int dircache_scan_and_build(IF_MV2(int volume,) struct dircache_entry *ce)
{
memset(ce, 0, sizeof(struct dircache_entry));
#ifdef HAVE_MULTIVOLUME
if (volume > 0)
{
/* broken for 100+ volumes because the format string is too small
* and we use that for size calculation */
const size_t max_len = VOL_ENUM_POS + 3;
ce->d_name = (d_names_start -= max_len);
snprintf(ce->d_name, max_len, VOL_NAMES, volume);
dircache_size += max_len;
ce->info.attribute = FAT_ATTR_DIRECTORY | FAT_ATTR_VOLUME;
ce->info.size = 0;
append_position = dircache_gen_next(ce);
ce = dircache_gen_down(ce);
}
#endif
struct fat_direntry direntry; /* ditto */
#ifdef HAVE_MULTIVOLUME
sab.volume = volume;
#endif
sab.dir = &sab_fat_dir;
sab.direntry = &direntry;
return sab_process_dir(0, ce);
}
#elif (CONFIG_PLATFORM & PLATFORM_HOSTED) /* PLATFORM_HOSTED */
static char sab_path[MAX_PATH];
static int sab_process_dir(struct dircache_entry *ce)
{
struct dirent_uncached *entry;
struct dircache_entry *first_ce = ce;
DIR_UNCACHED *dir = opendir_uncached(sab_path);
if(dir == NULL)
{
logf("Failed to opendir_uncached(%s)", sab_path);
return -1;
}
while((entry = readdir_uncached(dir)))
{
if(!strcmp(".", entry->d_name) ||
!strcmp("..", entry->d_name))
continue;
size_t size = strlen(entry->d_name) + 1;
ce->d_name = (d_names_start -= size);
ce->info = entry->info;
strcpy(ce->d_name, entry->d_name);
dircache_size += size;
if(entry->info.attribute & ATTR_DIRECTORY)
{
dircache_gen_down(ce);
if(ce->down == NULL)
{
closedir_uncached(dir);
return -1;
}
/* save current paths size */
int pathpos = strlen(sab_path);
/* append entry */
strlcpy(&sab_path[pathpos], "/", sizeof(sab_path) - pathpos);
strlcpy(&sab_path[pathpos+1], entry->d_name, sizeof(sab_path) - pathpos - 1);
int rc = sab_process_dir(ce->down);
/* restore path */
sab_path[pathpos] = '\0';
if(rc < 0)
{
closedir_uncached(dir);
return rc;
}
}
ce = dircache_gen_next(ce);
if(ce == NULL)
return -5;
/* When simulator is used, it's only safe to yield here. */
if(thread_enabled)
{
/* Stop if we got an external signal. */
if(check_event_queue())
return -1;
yield();
}
}
/* add "." and ".." */
ce->d_name = dot;
ce->info.attribute = ATTR_DIRECTORY;
ce->info.size = 0;
ce->down = first_ce;
ce = dircache_gen_next(ce);
ce->d_name = dotdot;
ce->info.attribute = ATTR_DIRECTORY;
ce->info.size = 0;
ce->down = first_ce->up;
closedir_uncached(dir);
return 0;
}
static int dircache_scan_and_build(IF_MV2(int volume,) struct dircache_entry *ce)
{
#ifdef HAVE_MULTIVOLUME
(void) volume;
#endif
memset(ce, 0, sizeof(struct dircache_entry));
strlcpy(sab_path, "/", sizeof sab_path);
return sab_process_dir(ce);
}
#endif /* PLATFORM_NATIVE */
/**
* Internal function to get a pointer to dircache_entry for a given filename.
* path: Absolute path to a file or directory (see comment)
* go_down: Returns the first entry of the directory given by the path (see comment)
*
* As a a special case, accept path="" as an alias for "/".
* Also if the path omits the first '/', it will be accepted.
*
* * If get_down=true:
* If path="/", the returned entry is the first of root directory (ie dircache_root)
* Otherwise, if 'entry' is the returned value when get_down=false,
* the functions returns entry->down (which can be NULL)
*
* * If get_down=false:
* If path="/chunk_1/chunk_2/.../chunk_n" then this functions returns the entry
* root_entry()->chunk_1->chunk_2->...->chunk_(n-1)
* Which means that
* dircache_get_entry(path)->d_name == chunk_n
*
* If path="/", the returned entry is NULL.
* If the entry doesn't exist, return NULL
*
* NOTE: this functions silently handles double '/'
*/
static struct dircache_entry* dircache_get_entry(const char *path, bool go_down)
{
char namecopy[MAX_PATH];
char* part;
char* end;
bool at_root = true;
struct dircache_entry *cache_entry = dircache_root;
strlcpy(namecopy, path, sizeof(namecopy));
for(part = strtok_r(namecopy, "/", &end); part; part = strtok_r(NULL, "/", &end))
{
/* If request another chunk, the current entry has to be directory
* and so cache_entry->down has to be non-NULL/
* Special case of root because it's already the first entry of the root directory
*
* NOTE: this is safe even if cache_entry->down is NULL */
if(!at_root)
cache_entry = cache_entry->down;
else
at_root = false;
/* scan dir for name */
while(cache_entry != NULL)
{
/* skip unused entries */
if(cache_entry->d_name == NULL)
{
cache_entry = cache_entry->next;
continue;
}
/* compare names */
if(!strcasecmp(part, cache_entry->d_name))
break;
/* go to next entry */
cache_entry = cache_entry->next;
}
/* handle not found case */
if(cache_entry == NULL)
return NULL;
}
/* NOTE: here cache_entry!=NULL so taking ->down is safe */
if(go_down)
return at_root ? cache_entry : cache_entry->down;
else
return at_root ? NULL : cache_entry;
}
#ifdef HAVE_EEPROM_SETTINGS
#define DIRCACHE_MAGIC 0x00d0c0a1
struct dircache_maindata {
long magic;
long size;
long entry_count;
long appflags;
struct dircache_entry *root_entry;
char *d_names_start;
};
/**
* Function to load the internal cache structure from disk to initialize
* the dircache really fast and little disk access.
*/
int dircache_load(void)
{
struct dircache_maindata maindata;
ssize_t bytes_read;
int fd;
if (dircache_initialized)
return -1;
logf("Loading directory cache");
dircache_size = 0;
fd = open_dircache_file(O_RDONLY, 0);
if (fd < 0)
return -2;
bytes_read = read(fd, &maindata, sizeof(struct dircache_maindata));
if (bytes_read != sizeof(struct dircache_maindata)
|| maindata.magic != DIRCACHE_MAGIC || maindata.size <= 0)
{
logf("Dircache file header error");
close(fd);
remove_dircache_file();
return -3;
}
allocated_size = maindata.size + DIRCACHE_RESERVE;
int handle = core_alloc("dircache", allocated_size);
dircache_root = core_get_data(handle);
/* needs to be struct-size aligned so that the pointer arithmetic below works */
ALIGN_BUFFER(dircache_root, allocated_size, sizeof(struct dircache_entry));
entry_count = maindata.entry_count;
appflags = maindata.appflags;
/* read the dircache file into memory,
* start with the struct dircache_entries */
ssize_t bytes_to_read = entry_count*sizeof(struct dircache_entry);
bytes_read = read(fd, dircache_root, bytes_to_read);
if (bytes_read != bytes_to_read)
{
logf("Dircache read failed #1");
return -6;
}
/* continue with the d_names. Fix up pointers to them if needed */
bytes_to_read = maindata.size - bytes_to_read;
d_names_start = (char*)dircache_root + allocated_size - bytes_to_read;
bytes_read = read(fd, d_names_start, bytes_to_read);
close(fd);
remove_dircache_file();
if (bytes_read != bytes_to_read)
{
logf("Dircache read failed #2");
return -7;
}
d_names_end = d_names_start + bytes_read;
dot = d_names_end - sizeof(".");
dotdot = dot - sizeof("..");
/* d_names are in reverse order, so the last entry points to the first string */
ptrdiff_t offset_d_names = maindata.d_names_start - d_names_start,
offset_entries = maindata.root_entry - dircache_root;
/* offset_entries is less likely to differ, so check if it's 0 in the loop
* offset_d_names however is almost always non-zero, since dircache_save()
* creates a file which causes the reserve buffer to be used. since
* we allocate a new, empty DIRCACHE_RESERVE here, the strings are
* farther behind */
if (offset_entries != 0 || offset_d_names != 0)
{
for(unsigned i = 0; i < entry_count; i++)
{
if (dircache_root[i].d_name)
dircache_root[i].d_name -= offset_d_names;
if (offset_entries == 0)
continue;
if (dircache_root[i].next)
dircache_root[i].next -= offset_entries;
if (dircache_root[i].up)
dircache_root[i].up -= offset_entries;
if (dircache_root[i].down)
dircache_root[i].down -= offset_entries;
}
}
/* Cache successfully loaded. */
dircache_size = maindata.size;
reserve_used = 0;
logf("Done, %ld KiB used", dircache_size / 1024);
dircache_initialized = true;
memset(fd_bindings, 0, sizeof(fd_bindings));
return 0;
}
/**
* Function to save the internal cache stucture to disk for fast loading
* on boot.
*/
int dircache_save(void)
{
struct dircache_maindata maindata;
int fd;
unsigned long bytes_written;
remove_dircache_file();
if (!dircache_initialized)
return -1;
logf("Saving directory cache");
fd = open_dircache_file(O_WRONLY | O_CREAT | O_TRUNC, 0666);
maindata.magic = DIRCACHE_MAGIC;
maindata.size = dircache_size;
maindata.root_entry = dircache_root;
maindata.d_names_start = d_names_start;
maindata.entry_count = entry_count;
maindata.appflags = appflags;
/* Save the info structure */
bytes_written = write(fd, &maindata, sizeof(struct dircache_maindata));
if (bytes_written != sizeof(struct dircache_maindata))
{
close(fd);
logf("dircache: write failed #1");
return -2;
}
/* Dump whole directory cache to disk
* start by writing the dircache_entries */
size_t bytes_to_write = entry_count*sizeof(struct dircache_entry);
bytes_written = write(fd, dircache_root, bytes_to_write);
if (bytes_written != bytes_to_write)
{
logf("dircache: write failed #2");
return -3;
}
/* continue with the d_names */
bytes_to_write = d_names_end - d_names_start;
bytes_written = write(fd, d_names_start, bytes_to_write);
close(fd);
if (bytes_written != bytes_to_write)
{
logf("dircache: write failed #3");
return -4;
}
return 0;
}
#endif /* HAVE_EEPROM_SETTINGS */
/**
* Internal function which scans the disk and creates the dircache structure.
*/
static int dircache_do_rebuild(void)
{
struct dircache_entry* root_entry;
unsigned int start_tick;
int i;
/* Measure how long it takes build the cache. */
start_tick = current_tick;
dircache_initializing = true;
appflags = 0;
/* reset dircache and alloc root entry */
entry_count = 0;
root_entry = allocate_entry();
#ifdef HAVE_MULTIVOLUME
append_position = root_entry;
for (i = NUM_VOLUMES; i >= 0; i--)
{
if (fat_ismounted(i))
{
#endif
cpu_boost(true);
#ifdef HAVE_MULTIVOLUME
if (dircache_scan_and_build(IF_MV2(i,) append_position) < 0)
#else
if (dircache_scan_and_build(IF_MV2(0,) root_entry) < 0)
#endif /* HAVE_MULTIVOLUME */
{
logf("dircache_scan_and_build failed");
cpu_boost(false);
dircache_size = 0;
dircache_initializing = false;
return -2;
}
cpu_boost(false);
#ifdef HAVE_MULTIVOLUME
}
}
#endif
logf("Done, %ld KiB used", dircache_size / 1024);
dircache_initialized = true;
dircache_initializing = false;
cache_build_ticks = current_tick - start_tick;
/* Initialized fd bindings. */
memset(fd_bindings, 0, sizeof(fd_bindings));
for (i = 0; i < fdbind_idx; i++)
dircache_bind(fdbind_cache[i].fd, fdbind_cache[i].path);
fdbind_idx = 0;
if (thread_enabled)
{
if (allocated_size - dircache_size < DIRCACHE_RESERVE)
reserve_used = DIRCACHE_RESERVE - (allocated_size - dircache_size);
}
return 1;
}
/**
* Internal thread that controls transparent cache building.
*/
static void dircache_thread(void)
{
struct queue_event ev;
while (1)
{
queue_wait(&dircache_queue, &ev);
switch (ev.id)
{
#ifdef HAVE_HOTSWAP
case SYS_FS_CHANGED:
if (!dircache_initialized)
break;
dircache_initialized = false;
#endif
case DIRCACHE_BUILD:
thread_enabled = true;
dircache_do_rebuild();
thread_enabled = false;
break ;
case DIRCACHE_STOP:
logf("Stopped the rebuilding.");
dircache_initialized = false;
break ;
#if (CONFIG_PLATFORM & PLATFORM_NATIVE)
case SYS_USB_CONNECTED:
usb_acknowledge(SYS_USB_CONNECTED_ACK);
usb_wait_for_disconnect(&dircache_queue);
break ;
#endif
}
}
}
static void generate_dot_d_names(void)
{
dot = (d_names_start -= sizeof("."));
dotdot = (d_names_start -= sizeof(".."));
dircache_size += sizeof(".") + sizeof("..");
strcpy(dot, ".");
strcpy(dotdot, "..");
}
/**
* Start scanning the disk to build the dircache.
* Either transparent or non-transparent build method is used.
*/
int dircache_build(int last_size)
{
if (dircache_initialized || thread_enabled)
return -3;
logf("Building directory cache");
#ifdef HAVE_EEPROM_SETTINGS
remove_dircache_file();
#endif
/* Background build, dircache has been previously allocated */
if (allocated_size > 0)
{
d_names_start = d_names_end;
dircache_size = 0;
reserve_used = 0;
thread_enabled = true;
dircache_initializing = true;
generate_dot_d_names();
queue_post(&dircache_queue, DIRCACHE_BUILD, 0);
return 2;
}
if (last_size > DIRCACHE_RESERVE && last_size < DIRCACHE_LIMIT )
{
int handle;
allocated_size = last_size + DIRCACHE_RESERVE;
handle = core_alloc("dircache", allocated_size);
dircache_root = core_get_data(handle);
ALIGN_BUFFER(dircache_root, allocated_size, sizeof(struct dircache_entry));
d_names_start = d_names_end = ((char*)dircache_root)+allocated_size-1;
dircache_size = 0;
thread_enabled = true;
generate_dot_d_names();
/* Start a transparent rebuild. */
queue_post(&dircache_queue, DIRCACHE_BUILD, 0);
return 3;
}
/* We'll use the entire audiobuf to allocate the dircache
* struct dircache_entrys are allocated from the beginning
* and their corresponding d_name from the end
* after generation the buffer will be compacted with DIRCACHE_RESERVE
* free bytes inbetween */
size_t got_size;
int handle = core_alloc_maximum("dircache", &got_size, NULL);
char* buf = core_get_data(handle);
dircache_root = (struct dircache_entry*)ALIGN_UP(buf,
sizeof(struct dircache_entry));
d_names_start = d_names_end = buf + got_size - 1;
dircache_size = 0;
generate_dot_d_names();
/* Start a non-transparent rebuild. */
int res = dircache_do_rebuild();
if (res < 0)
goto fail;
/* now compact the dircache buffer */
char* dst = ((char*)&dircache_root[entry_count] + DIRCACHE_RESERVE);
ptrdiff_t offset = d_names_start - dst;
if (offset <= 0) /* something went wrong */
{
res = -1;
goto fail;
}
/* memmove d_names down, there's a possibility of overlap
* equivaent to dircache_size - entry_count*sizeof(struct dircache_entry) */
ptrdiff_t size_to_move = d_names_end - d_names_start;
memmove(dst, d_names_start, size_to_move);
/* fix up pointers to the d_names */
for(unsigned i = 0; i < entry_count; i++)
dircache_root[i].d_name -= offset;
d_names_start -= offset;
d_names_end -= offset;
dot -= offset;
dotdot -= offset;
/* equivalent to dircache_size + DIRCACHE_RESERVE + align */
allocated_size = (d_names_end - buf);
reserve_used = 0;
core_shrink(handle, dircache_root, allocated_size);
return res;
fail:
dircache_disable();
core_free(handle);
return res;
}
/**
* Steal the allocated dircache buffer and disable dircache.
*/
void* dircache_steal_buffer(size_t *size)
{
dircache_disable();
if (dircache_size == 0)
{
*size = 0;
return NULL;
}
*size = dircache_size + (DIRCACHE_RESERVE-reserve_used);
return dircache_root;
}
/**
* Main initialization function that must be called before any other
* operations within the dircache.
*/
void dircache_init(void)
{
int i;
int thread_id __attribute__((unused));
dircache_initialized = false;
dircache_initializing = false;
memset(opendirs, 0, sizeof(opendirs));
for (i = 0; i < MAX_OPEN_DIRS; i++)
{
opendirs[i].theent.d_name = opendir_dnames[i];
}
queue_init(&dircache_queue, true);
thread_id = create_thread(dircache_thread, dircache_stack,
sizeof(dircache_stack), 0, dircache_thread_name
IF_PRIO(, PRIORITY_BACKGROUND)
IF_COP(, CPU));
#ifdef HAVE_IO_PRIORITY
thread_set_io_priority(thread_id,IO_PRIORITY_BACKGROUND);
#endif
}
/**
* Returns true if dircache has been initialized and is ready to be used.
*/
bool dircache_is_enabled(void)
{
return dircache_initialized;
}
/**
* Returns true if dircache is being initialized.
*/
bool dircache_is_initializing(void)
{
return dircache_initializing || thread_enabled;
}
/**
* Set application flags used to determine if dircache is still intact.
*/
void dircache_set_appflag(long mask)
{
appflags |= mask;
}
/**
* Get application flags used to determine if dircache is still intact.
*/
bool dircache_get_appflag(long mask)
{
return dircache_is_enabled() && (appflags & mask);
}
/**
* Returns the current number of entries (directories and files) in the cache.
*/
int dircache_get_entry_count(void)
{
return entry_count;
}
/**
* Returns the allocated space for dircache (without reserve space).
*/
int dircache_get_cache_size(void)
{
return dircache_is_enabled() ? dircache_size : 0;
}
/**
* Returns how many bytes of the reserve allocation for live cache
* updates have been used.
*/
int dircache_get_reserve_used(void)
{
return dircache_is_enabled() ? reserve_used : 0;
}
/**
* Returns the time in kernel ticks that took to build the cache.
*/
int dircache_get_build_ticks(void)
{
return dircache_is_enabled() ? cache_build_ticks : 0;
}
/**
* Disables the dircache. Usually called on shutdown or when
* accepting a usb connection.
*/
void dircache_disable(void)
{
int i;
bool cache_in_use;
if (thread_enabled)
queue_post(&dircache_queue, DIRCACHE_STOP, 0);
while (thread_enabled)
sleep(1);
dircache_initialized = false;
logf("Waiting for cached dirs to release");
do {
cache_in_use = false;
for (i = 0; i < MAX_OPEN_DIRS; i++) {
if (!opendirs[i].regulardir && opendirs[i].busy)
{
cache_in_use = true;
sleep(1);
break ;
}
}
} while (cache_in_use) ;
logf("Cache released");
entry_count = 0;
}
/**
* Usermode function to return dircache_entry index to the given path.
*/
static int dircache_get_entry_id_ex(const char *filename, bool go_down)
{
if (!dircache_initialized || filename == NULL)
return -1;
struct dircache_entry* res = dircache_get_entry(filename, go_down);
return res ? res - dircache_root : -1;
}
int dircache_get_entry_id(const char* filename)
{
return dircache_get_entry_id_ex(filename, false);
}
/**
* Internal: Get the startcluster for the index
*/
long _dircache_get_entry_startcluster(int id)
{
return get_entry(id)->startcluster;
}
/**
* Internal: Get the struct dirinfo for the index
*/
struct dirinfo* _dircache_get_entry_dirinfo(int id)
{
return &get_entry(id)->info;
}
/*
* build a path from an entry upto the root using recursion
*
* it appends '/' after strlcat, therefore buf[0] needs to be prepared with '/'
* and it will leave a trailing '/'
*
* returns the position of that trailing '/' so it can be deleted afterwards
* (or, in case of truncation, the position of the nul byte */
static size_t copy_path_helper(const struct dircache_entry *entry, char *buf, size_t size)
{
int offset = 1;
/* has parent? */
if (entry->up)
offset += copy_path_helper(entry->up, buf, size);
size_t len = strlcpy(buf+offset, entry->d_name, size - offset) + offset;
if (len < size)
{
buf[len++] = '/';
buf[len] = '\0';
}
return len-1;
}
/**
* Function to copy the full absolute path from dircache to the given buffer
* using the given dircache_entry pointer.
*
* Returns the size of the resulting string, or 0 if an error occured
*/
size_t dircache_copy_path(int index, char *buf, size_t size)
{
if (!size || !buf || index < 0)
return 0;
buf[0] = '/';
size_t res = copy_path_helper(&dircache_root[index], buf, size - 1);
/* fixup trailing '/' */
buf[res] = '\0';
return res;
}
/* --- Directory cache live updating functions --- */
static int block_until_ready(void)
{
/* Block until dircache has been built. */
while (!dircache_initialized && dircache_is_initializing())
sleep(1);
if (!dircache_initialized)
return -1;
return 0;
}
static struct dircache_entry* dircache_new_entry(const char *path, int attribute)
{
struct dircache_entry *entry;
char basedir[MAX_PATH*2];
char *new;
long last_cache_size = dircache_size;
strlcpy(basedir, path, sizeof(basedir));
new = strrchr(basedir, '/');
if (new == NULL)
{
logf("error occurred");
dircache_initialized = false;
return NULL;
}
*new = '\0';
new++;
entry = dircache_get_entry(basedir, true);
if (entry == NULL)
{
logf("basedir not found!");
logf("%s", basedir);
dircache_initialized = false;
return NULL;
}
if (reserve_used + 2*sizeof(struct dircache_entry) + strlen(new)+1
>= DIRCACHE_RESERVE)
{
logf("not enough space");
dircache_initialized = false;
return NULL;
}
while (entry->next != NULL)
entry = entry->next;
if (entry->d_name != NULL)
{
entry = dircache_gen_next(entry);
if (entry == NULL)
{
dircache_initialized = false;
return NULL;
}
}
size_t size = strlen(new) + 1;
entry->d_name = (d_names_start -= size);
entry->startcluster = 0;
memset(&entry->info, 0, sizeof(entry->info));
entry->info.attribute = attribute;
strcpy(entry->d_name, new);
dircache_size += size;
if (attribute & ATTR_DIRECTORY)
{
logf("gen_down");
dircache_gen_down(entry);
}
reserve_used += dircache_size - last_cache_size;
return entry;
}
void dircache_bind(int fd, const char *path)
{
struct dircache_entry *entry;
/* Queue requests until dircache has been built. */
if (!dircache_initialized && dircache_is_initializing())
{
if (fdbind_idx >= MAX_PENDING_BINDINGS)
return ;
strlcpy(fdbind_cache[fdbind_idx].path, path,
sizeof(fdbind_cache[fdbind_idx].path));
fdbind_cache[fdbind_idx].fd = fd;
fdbind_idx++;
return ;
}
if (!dircache_initialized)
return ;
logf("bind: %d/%s", fd, path);
entry = dircache_get_entry(path, false);
if (entry == NULL)
{
logf("not found!");
dircache_initialized = false;
return ;
}
fd_bindings[fd] = entry;
}
void dircache_update_filesize(int fd, long newsize, long startcluster)
{
if (!dircache_initialized || fd < 0)
return ;
if (fd_bindings[fd] == NULL)
{
logf("dircache fd(%d) access error", fd);
dircache_initialized = false;
return ;
}
fd_bindings[fd]->info.size = newsize;
fd_bindings[fd]->startcluster = startcluster;
}
void dircache_update_filetime(int fd)
{
#if CONFIG_RTC == 0
(void)fd;
#else
short year;
struct tm *now = get_time();
if (!dircache_initialized || fd < 0)
return ;
if (fd_bindings[fd] == NULL)
{
logf("dircache fd access error");
dircache_initialized = false;
return ;
}
year = now->tm_year+1900-1980;
fd_bindings[fd]->info.wrtdate = (((year)&0x7f)<<9) |
(((now->tm_mon+1)&0xf)<<5) |
(((now->tm_mday)&0x1f));
fd_bindings[fd]->info.wrttime = (((now->tm_hour)&0x1f)<<11) |
(((now->tm_min)&0x3f)<<5) |
(((now->tm_sec/2)&0x1f));
#endif
}
void dircache_mkdir(const char *path)
{ /* Test ok. */
if (block_until_ready())
return ;
logf("mkdir: %s", path);
dircache_new_entry(path, ATTR_DIRECTORY);
}
void dircache_rmdir(const char *path)
{ /* Test ok. */
struct dircache_entry *entry;
if (block_until_ready())
return ;
logf("rmdir: %s", path);
entry = dircache_get_entry(path, false);
if (entry == NULL || entry->down == NULL)
{
logf("not found or not a directory!");
dircache_initialized = false;
return ;
}
entry->down = NULL;
entry->d_name = NULL;
}
/* Remove a file from cache */
void dircache_remove(const char *name)
{ /* Test ok. */
struct dircache_entry *entry;
if (block_until_ready())
return ;
logf("remove: %s", name);
entry = dircache_get_entry(name, false);
if (entry == NULL)
{
logf("not found!");
dircache_initialized = false;
return ;
}
entry->d_name = NULL;
}
void dircache_rename(const char *oldpath, const char *newpath)
{ /* Test ok. */
struct dircache_entry *entry, *newentry;
struct dircache_entry oldentry;
char absolute_path[MAX_PATH*2];
char *p;
if (block_until_ready())
return ;
logf("rename: %s->%s", oldpath, newpath);
entry = dircache_get_entry(oldpath, false);
if (entry == NULL)
{
logf("not found!");
dircache_initialized = false;
return ;
}
/* Delete the old entry. */
entry->d_name = NULL;
/** If we rename the same filename twice in a row, we need to
* save the data, because the entry will be re-used. */
oldentry = *entry;
/* Generate the absolute path for destination if necessary. */
if (newpath[0] != '/')
{
strlcpy(absolute_path, oldpath, sizeof(absolute_path));
p = strrchr(absolute_path, '/');
if (!p)
{
logf("Invalid path");
dircache_initialized = false;
return ;
}
*p = '\0';
strlcpy(p, absolute_path, sizeof(absolute_path)-strlen(p));
newpath = absolute_path;
}
newentry = dircache_new_entry(newpath, entry->info.attribute);
if (newentry == NULL)
{
dircache_initialized = false;
return ;
}
newentry->down = oldentry.down;
newentry->startcluster = oldentry.startcluster;
newentry->info.size = oldentry.info.size;
newentry->info.wrtdate = oldentry.info.wrtdate;
newentry->info.wrttime = oldentry.info.wrttime;
}
void dircache_add_file(const char *path, long startcluster)
{
struct dircache_entry *entry;
if (block_until_ready())
return ;
logf("add file: %s", path);
entry = dircache_new_entry(path, 0);
if (entry == NULL)
return ;
entry->startcluster = startcluster;
}
static bool is_disable_msg_pending(void)
{
return check_event_queue();
}
DIR_CACHED* opendir_cached(const char* name)
{
int dd;
DIR_CACHED* pdir = opendirs;
if ( name[0] != '/' )
{
DEBUGF("Only absolute paths supported right now\n");
return NULL;
}
/* find a free dir descriptor */
for ( dd=0; dd<MAX_OPEN_DIRS; dd++, pdir++)
if ( !pdir->busy )
break;
if ( dd == MAX_OPEN_DIRS )
{
DEBUGF("Too many dirs open\n");
errno = EMFILE;
return NULL;
}
pdir->busy = true;
if (!dircache_initialized || is_disable_msg_pending())
{
pdir->internal_entry = -1;
pdir->regulardir = opendir_uncached(name);
}
else
{
pdir->regulardir = NULL;
pdir->internal_entry = dircache_get_entry_id_ex(name, true);
pdir->theent.info.attribute = -1; /* used to make readdir_cached aware of the first call */
}
if (pdir->internal_entry == -1 && pdir->regulardir == NULL)
{
pdir->busy = false;
return NULL;
}
return pdir;
}
struct dirent_cached* readdir_cached(DIR_CACHED* dir)
{
struct dircache_entry *ce = get_entry(dir->internal_entry);
struct dirent_uncached *regentry;
if (!dir->busy)
return NULL;
if (dir->regulardir != NULL)
{
regentry = readdir_uncached(dir->regulardir);
if (regentry == NULL)
return NULL;
strlcpy(dir->theent.d_name, regentry->d_name, MAX_PATH);
dir->theent.startcluster = regentry->startcluster;
dir->theent.info = regentry->info;
return &dir->theent;
}
/* if theent.attribute=-1 then this is the first call */
/* otherwise, this is is not so we first take the entry's ->next */
/* NOTE: normal file can't have attribute=-1 */
if(dir->theent.info.attribute != -1)
ce = ce->next;
/* skip unused entries */
while(ce != NULL && ce->d_name == NULL)
ce = ce->next;
if (ce == NULL)
return NULL;
strlcpy(dir->theent.d_name, ce->d_name, MAX_PATH);
/* Can't do `dir->theent = *ce`
because that modifies the d_name pointer. */
dir->theent.startcluster = ce->startcluster;
dir->theent.info = ce->info;
dir->internal_entry = ce - dircache_root;
//logf("-> %s", ce->d_name);
return &dir->theent;
}
int closedir_cached(DIR_CACHED* dir)
{
if (!dir->busy)
return -1;
dir->busy=false;
if (dir->regulardir != NULL)
return closedir_uncached(dir->regulardir);
return 0;
}
int mkdir_cached(const char *name)
{
int rc=mkdir_uncached(name);
if (rc >= 0)
dircache_mkdir(name);
return(rc);
}
int rmdir_cached(const char* name)
{
int rc=rmdir_uncached(name);
if(rc >= 0)
dircache_rmdir(name);
return(rc);
}
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