Make the I/O semantics functionality in Coffee unconditional so that the API becomes consistent across platforms.

Change certain CPP conditionals into C conditionals, which should be possible for the compiler to optimize at runtime. This makes the source code easier to read.
This commit is contained in:
Nicolas Tsiftes 2016-06-13 15:55:58 +02:00
parent 30e820ffa5
commit 5010309005
3 changed files with 32 additions and 57 deletions

View File

@ -75,12 +75,6 @@
#error "Cannot have COFFEE_APPEND_ONLY set when COFFEE_MICRO_LOGS is set."
#endif
/* I/O semantics can be set on file descriptors in order to optimize
file access on certain storage types. */
#ifndef COFFEE_IO_SEMANTICS
#define COFFEE_IO_SEMANTICS 0
#endif
/*
* Prevent sectors from being erased directly after file removal.
* This will level the wear across sectors better, but may lead
@ -94,24 +88,29 @@
#error COFFEE_START must point to the first byte in a sector.
#endif
/* File descriptor flags. */
#define COFFEE_FD_FREE 0x0
#define COFFEE_FD_READ 0x1
#define COFFEE_FD_WRITE 0x2
#define COFFEE_FD_APPEND 0x4
/* File object flags. */
#define COFFEE_FILE_MODIFIED 0x1
#define INVALID_PAGE ((coffee_page_t)-1)
/* Internal Coffee markers. */
#define INVALID_PAGE ((coffee_page_t)-1)
#define UNKNOWN_OFFSET ((cfs_offset_t)-1)
#define REMOVE_LOG 1
#define CLOSE_FDS 1
#define ALLOW_GC 1
/* File removal actions. They can have the same values because
they are passed as separate parameters. */
#define REMOVE_LOG 1
#define CLOSE_FDS 1
#define ALLOW_GC 1
/* "Greedy" garbage collection erases as many sectors as possible. */
#define GC_GREEDY 0
#define GC_GREEDY 0
/* "Reluctant" garbage collection stops after erasing one sector. */
#define GC_RELUCTANT 1
#define GC_RELUCTANT 1
/* File descriptor macros. */
#define FD_VALID(fd) ((fd) >= 0 && (fd) < COFFEE_FD_SET_SIZE && \
@ -176,9 +175,7 @@ struct file_desc {
cfs_offset_t offset;
struct file *file;
uint8_t flags;
#if COFFEE_IO_SEMANTICS
uint8_t io_flags;
#endif
};
/* The file header structure mimics the representation of file headers
@ -221,11 +218,9 @@ static void
read_header(struct file_header *hdr, coffee_page_t page)
{
COFFEE_READ(hdr, sizeof(*hdr), page * COFFEE_PAGE_SIZE);
#if DEBUG
if(HDR_ACTIVE(*hdr) && !HDR_VALID(*hdr)) {
PRINTF("Invalid header at page %u!\n", (unsigned)page);
if(DEBUG && HDR_ACTIVE(*hdr) && !HDR_VALID(*hdr)) {
PRINTF("Coffee: Invalid header at page %u!\n", (unsigned)page);
}
#endif
}
/*---------------------------------------------------------------------------*/
static cfs_offset_t
@ -561,8 +556,8 @@ find_contiguous_pages(coffee_page_t amount)
}
/*---------------------------------------------------------------------------*/
static int
remove_by_page(coffee_page_t page, int remove_log, int close_fds,
int gc_allowed)
remove_by_page(coffee_page_t page, int remove_log,
int close_fds, int gc_allowed)
{
struct file_header hdr;
int i;
@ -600,11 +595,9 @@ remove_by_page(coffee_page_t page, int remove_log, int close_fds,
}
}
#if !COFFEE_EXTENDED_WEAR_LEVELLING
if(gc_allowed) {
if(!COFFEE_EXTENDED_WEAR_LEVELLING && gc_allowed) {
collect_garbage(GC_RELUCTANT);
}
#endif
return 0;
}
@ -1104,19 +1097,13 @@ cfs_read(int fd, void *buf, unsigned size)
fdp = &coffee_fd_set[fd];
file = fdp->file;
#if COFFEE_IO_SEMANTICS
if(fdp->io_flags & CFS_COFFEE_IO_ENSURE_READ_LENGTH) {
while(fdp->offset + size > file->end) {
((char*)buf)[--size] = 0;
((char *)buf)[--size] = '\0';
}
} else {
#endif
if(fdp->offset + size > file->end) {
size = file->end - fdp->offset;
}
#if COFFEE_IO_SEMANTICS
} else if(fdp->offset + size > file->end) {
size = file->end - fdp->offset;
}
#endif
/* If the file is not modified, read directly from the file extent. */
if(!FILE_MODIFIED(file)) {
@ -1173,28 +1160,20 @@ cfs_write(int fd, const void *buf, unsigned size)
file = fdp->file;
/* Attempt to extend the file if we try to write past the end. */
#if COFFEE_IO_SEMANTICS
if(!(fdp->io_flags & CFS_COFFEE_IO_FIRM_SIZE)) {
#endif
while(size + fdp->offset + sizeof(struct file_header) >
(file->max_pages * COFFEE_PAGE_SIZE)) {
if(merge_log(file->page, 1) < 0) {
return -1;
while(size + fdp->offset + sizeof(struct file_header) >
(file->max_pages * COFFEE_PAGE_SIZE)) {
if(merge_log(file->page, 1) < 0) {
return -1;
}
file = fdp->file;
PRINTF("Extended the file at page %u\n", (unsigned)file->page);
}
file = fdp->file;
PRINTF("Extended the file at page %u\n", (unsigned)file->page);
}
#if COFFEE_IO_SEMANTICS
}
#endif
#if COFFEE_MICRO_LOGS
#if COFFEE_IO_SEMANTICS
if(!(fdp->io_flags & CFS_COFFEE_IO_FLASH_AWARE) &&
(FILE_MODIFIED(file) || fdp->offset < file->end)) {
#else
if(FILE_MODIFIED(file) || fdp->offset < file->end) {
#endif
need_dummy_write = 0;
for(bytes_left = size; bytes_left > 0;) {
lp.offset = fdp->offset;
@ -1236,16 +1215,14 @@ cfs_write(int fd, const void *buf, unsigned size)
}
} else {
#endif /* COFFEE_MICRO_LOGS */
#if COFFEE_APPEND_ONLY
if(fdp->offset < file->end) {
return -1;
}
#endif /* COFFEE_APPEND_ONLY */
if(COFFEE_APPEND_ONLY && fdp->offset < file->end) {
return -1;
}
COFFEE_WRITE(buf, size, absolute_offset(file->page, fdp->offset));
fdp->offset += size;
COFFEE_WRITE(buf, size, absolute_offset(file->page, fdp->offset));
fdp->offset += size;
#if COFFEE_MICRO_LOGS
}
}
#endif /* COFFEE_MICRO_LOGS */
if(fdp->offset > file->end) {

View File

@ -55,7 +55,6 @@
#define COFFEE_LOG_SIZE 8192
#define COFFEE_LOG_TABLE_LIMIT 256
#define COFFEE_MICRO_LOGS 0
#define COFFEE_IO_SEMANTICS 1
#define COFFEE_WRITE(buf, size, offset) \
xmem_pwrite((char *)(buf), (size), COFFEE_START + (offset))

View File

@ -59,7 +59,6 @@
#endif
#define COFFEE_LOG_SIZE 1024
#define COFFEE_IO_SEMANTICS 1
#define COFFEE_APPEND_ONLY 0
#define COFFEE_MICRO_LOGS 1