dfs_seq_file.c 文件参考

#include <dfs_seq_file.h>
#include <dfs_dentry.h>
#include <rtdbg.h>

dfs_seq_file.c 的引用(Include)关系图:

浏览该文件的源代码.

宏定义
#define	DBG_TAG   "DFS.seq"
#define	DBG_LVL   DBG_WARNING
#define	PAGE_SIZE   4096

函数
int	dfs_seq_open (struct dfs_file *file, const struct dfs_seq_ops *ops)
ssize_t	dfs_seq_read (struct dfs_file *file, void *buf, size_t size, off_t *pos)
off_t	dfs_seq_lseek (struct dfs_file *file, off_t offset, int whence)
int	dfs_seq_release (struct dfs_file *file)
void	dfs_seq_vprintf (struct dfs_seq_file *seq, const char *f, va_list args)
void	dfs_seq_printf (struct dfs_seq_file *seq, const char *f,...)
void	dfs_seq_putc (struct dfs_seq_file *seq, char c)
void	dfs_seq_puts (struct dfs_seq_file *seq, const char *s)
int	dfs_seq_write (struct dfs_seq_file *seq, const void *data, size_t len)
void	dfs_seq_pad (struct dfs_seq_file *seq, char c)

宏定义说明

DBG_TAG

#define DBG_TAG   "DFS.seq"

在文件 dfs_seq_file.c 第 13 行定义.

DBG_LVL

#define DBG_LVL   DBG_WARNING

在文件 dfs_seq_file.c 第 14 行定义.

PAGE_SIZE

#define PAGE_SIZE   4096

在文件 dfs_seq_file.c 第 18 行定义.

函数说明

dfs_seq_open()

int dfs_seq_open	(	struct dfs_file *	file,
		const struct dfs_seq_ops *	ops )

在文件 dfs_seq_file.c 第 31 行定义.

{
    struct dfs_seq_file *seq;
 
    if (!ops)
    {
        LOG_E("dfs_seq_open: ops = null, pathname: %s\n", file->dentry->pathname);
        return -EINVAL;
    }
 
    if (file->data)
    {
        LOG_W("dfs_seq_open: file->data != null\n");
    }
 
    seq = rt_calloc(1, sizeof(struct dfs_seq_file));
    if (!seq)
        return -ENOMEM;
 
    file->data = seq;
 
    rt_mutex_init(&seq->lock, "dfs_seq", RT_IPC_FLAG_PRIO);
 
    seq->ops = ops;
    seq->file = file;
 
    return 0;
}

引用了 dfs_file::data, dfs_file::dentry, dfs_seq_file::file, dfs_seq_file::lock, LOG_E, LOG_W, dfs_seq_file::ops, dfs_dentry::pathname, rt_calloc(), RT_IPC_FLAG_PRIO , 以及 rt_mutex_init().

函数调用图:

dfs_seq_read()

ssize_t dfs_seq_read	(	struct dfs_file *	file,
		void *	buf,
		size_t	size,
		off_t *	pos )

在文件 dfs_seq_file.c 第 114 行定义.

{
    struct dfs_seq_file *seq = file->data;
    size_t copied = 0;
    size_t n;
    void *p;
    int err = 0;
 
    if (!size)
        return 0;
 
    rt_mutex_take(&seq->lock, RT_WAITING_FOREVER);
 
    /*
     * if request is to read from zero offset, reset iterator to first
     * record as it might have been already advanced by previous requests
     */
    if (*pos == 0)
    {
        seq->index = 0;
        seq->count = 0;
    }
 
    /* Don't assume ki_pos is where we left it */
    if (*pos != seq->read_pos)
    {
        while ((err = dfs_seq_traverse(seq, *pos)) == -EAGAIN)
            ;
        if (err)
        {
            /* With prejudice... */
            seq->read_pos = 0;
            seq->index = 0;
            seq->count = 0;
            goto Done;
        }
        else
        {
            seq->read_pos = *pos;
        }
    }
 
    /* grab buffer if we didn't have one */
    if (!seq->buf)
    {
        seq->buf = dfs_seq_alloc(seq->size = PAGE_SIZE);
        if (!seq->buf)
            goto Enomem;
    }
    // something left in the buffer - copy it out first
    if (seq->count)
    {
        n = seq->count > size ? size : seq->count;
        rt_memcpy((char *)buf + copied, seq->buf + seq->from, n);
        size -= n;
        seq->count -= n;
        seq->from += n;
        copied += n;
        if (seq->count) // hadn't managed to copy everything
            goto Done;
    }
    // get a non-empty record in the buffer
    seq->from = 0;
    p = seq->ops->start(seq, &seq->index);
    while (p)
    {
        err = seq->ops->show(seq, p);
        if (err < 0) // hard error
            break;
        if (err) // ->show() says "skip it"
            seq->count = 0;
        if (!seq->count)
        { // empty record
            p = seq->ops->next(seq, p, &seq->index);
            continue;
        }
        if (!dfs_seq_is_full(seq)) // got it
            goto Fill;
        // need a bigger buffer
        seq->ops->stop(seq, p);
        rt_free(seq->buf);
        seq->count = 0;
        seq->buf = dfs_seq_alloc(seq->size <<= 1);
        if (!seq->buf)
            goto Enomem;
        p = seq->ops->start(seq, &seq->index);
    }
    // EOF or an error
    seq->ops->stop(seq, p);
    seq->count = 0;
    goto Done;
Fill:
    // one non-empty record is in the buffer; if they want more,
    // try to fit more in, but in any case we need to advance
    // the iterator once for every record shown.
    while (1)
    {
        size_t offs = seq->count;
        off_t pos = seq->index;
 
        p = seq->ops->next(seq, p, &seq->index);
        if (pos == seq->index)
        {
            LOG_W(".next function %p did not update position index\n", seq->ops->next);
            seq->index++;
        }
        if (!p) // no next record for us
            break;
        if (seq->count >= size)
            break;
        err = seq->ops->show(seq, p);
        if (err > 0)
        { // ->show() says "skip it"
            seq->count = offs;
        }
        else if (err || dfs_seq_is_full(seq))
        {
            seq->count = offs;
            break;
        }
    }
    seq->ops->stop(seq, p);
    n = seq->count > size ? size : seq->count;
    rt_memcpy((char *)buf + copied, seq->buf, n);
    size -= n;
    copied += n;
    seq->count -= n;
    seq->from = n;
Done:
    if (!copied)
    {
        copied = seq->count ? -EFAULT : err;
    }
    else
    {
        *pos += copied;
        seq->read_pos += copied;
    }
    rt_mutex_release(&seq->lock);
    return copied;
Enomem:
    err = -ENOMEM;
    goto Done;
}

引用了 dfs_seq_file::buf, dfs_seq_file::count, dfs_file::data, dfs_seq_file::file, dfs_seq_file::from, dfs_seq_file::index, dfs_seq_file::lock, LOG_W, dfs_seq_ops::next, dfs_seq_file::ops, PAGE_SIZE, dfs_seq_file::read_pos, rt_free(), rt_mutex_release(), rt_mutex_take(), RT_WAITING_FOREVER, dfs_seq_ops::show, dfs_seq_file::size, dfs_seq_ops::start , 以及 dfs_seq_ops::stop.

函数调用图:

dfs_seq_lseek()

off_t dfs_seq_lseek	(	struct dfs_file *	file,
		off_t	offset,
		int	whence )

在文件 dfs_seq_file.c 第 259 行定义.

{
    struct dfs_seq_file *seq = file->data;
    off_t retval = -EINVAL;
 
    rt_mutex_take(&seq->lock, RT_WAITING_FOREVER);
 
    switch (whence)
    {
    case SEEK_CUR:
        offset += file->fpos;
    case SEEK_SET:
        if (offset < 0)
            break;
        retval = offset;
        if (offset != seq->read_pos)
        {
            while ((retval = dfs_seq_traverse(seq, offset)) == -EAGAIN);
            if (retval)
            {
                /* with extreme prejudice... */
                retval = 0;
                seq->read_pos = 0;
                seq->index = 0;
                seq->count = 0;
            }
            else
            {
                seq->read_pos = offset;
                retval = offset;
            }
        }
    }
 
    rt_mutex_release(&seq->lock);
 
    return retval;
}

引用了 dfs_seq_file::count, dfs_file::data, dfs_seq_file::file, dfs_file::fpos, dfs_seq_file::index, dfs_seq_file::lock, dfs_seq_file::read_pos, rt_mutex_release(), rt_mutex_take() , 以及 RT_WAITING_FOREVER.

函数调用图:

dfs_seq_release()

int dfs_seq_release

(

struct dfs_file *

file

)

在文件 dfs_seq_file.c 第 298 行定义.

{
    struct dfs_seq_file *seq = file->data;
 
    if (seq)
    {
        rt_mutex_detach(&seq->lock);
        if (seq->buf)
        {
            rt_free(seq->buf);
        }
        rt_free(seq);
    }
 
    return 0;
}

引用了 dfs_seq_file::buf, dfs_file::data, dfs_seq_file::file, dfs_seq_file::lock, rt_free() , 以及 rt_mutex_detach().

函数调用图:

dfs_seq_vprintf()

void dfs_seq_vprintf	(	struct dfs_seq_file *	seq,
		const char *	f,
		va_list	args )

在文件 dfs_seq_file.c 第 315 行定义.

{
    int len;
 
    if (seq->count < seq->size)
    {
        len = vsnprintf(seq->buf + seq->count, seq->size - seq->count, f, args);
        if (seq->count + len < seq->size)
        {
            seq->count += len;
            return;
        }
    }
    dfs_seq_overflow(seq);
}

引用了 dfs_seq_file::buf, dfs_seq_file::count , 以及 dfs_seq_file::size.

这是这个函数的调用关系图:

dfs_seq_printf()

void dfs_seq_printf	(	struct dfs_seq_file *	seq,
		const char *	f,
			... )

在文件 dfs_seq_file.c 第 331 行定义.

{
    va_list args;
 
    va_start(args, f);
    dfs_seq_vprintf(seq, f, args);
    va_end(args);
}

引用了 dfs_seq_vprintf().

函数调用图:

dfs_seq_putc()

void dfs_seq_putc	(	struct dfs_seq_file *	seq,
		char	c )

write char to buffer

在文件 dfs_seq_file.c 第 343 行定义.

{
    if (seq->count < seq->size)
    {
        seq->buf[seq->count++] = c;
    }
}

引用了 dfs_seq_file::buf, dfs_seq_file::count , 以及 dfs_seq_file::size.

这是这个函数的调用关系图:

dfs_seq_puts()

void dfs_seq_puts	(	struct dfs_seq_file *	seq,
		const char *	s )

write string to buffer

在文件 dfs_seq_file.c 第 354 行定义.

{
    int len = strlen(s);
 
    if (seq->count + len >= seq->size)
    {
        dfs_seq_overflow(seq);
        return;
    }
    rt_memcpy(seq->buf + seq->count, s, len);
    seq->count += len;
}

引用了 dfs_seq_file::buf, dfs_seq_file::count , 以及 dfs_seq_file::size.

dfs_seq_write()

int dfs_seq_write	(	struct dfs_seq_file *	seq,
		const void *	data,
		size_t	len )

write arbitrary data to buffer

在文件 dfs_seq_file.c 第 370 行定义.

{
    if (seq->count + len < seq->size)
    {
        rt_memcpy(seq->buf + seq->count, data, len);
        seq->count += len;
        return 0;
    }
    dfs_seq_overflow(seq);
    return -1;
}

引用了 dfs_seq_file::buf, dfs_seq_file::count, dfs_seq_file::data , 以及 dfs_seq_file::size.

dfs_seq_pad()

void dfs_seq_pad	(	struct dfs_seq_file *	seq,
		char	c )

write padding spaces to buffer

在文件 dfs_seq_file.c 第 385 行定义.

{
    int size = seq->pad_until - seq->count;
 
    if (size > 0)
    {
        if (size + seq->count > seq->size)
        {
            dfs_seq_overflow(seq);
            return;
        }
        rt_memset(seq->buf + seq->count, ' ', size);
        seq->count += size;
    }
 
    if (c)
    {
        dfs_seq_putc(seq, c);
    }
}

引用了 dfs_seq_file::buf, dfs_seq_file::count, dfs_seq_putc(), dfs_seq_file::pad_until , 以及 dfs_seq_file::size.

函数调用图: