hfile.h

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/*  hfile.h -- buffered low-level input/output streams.

    Copyright (C) 2013-2014 Genome Research Ltd.

    Author: John Marshall <jm18@sanger.ac.uk>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.  */

#ifndef HTSLIB_HFILE_H
#define HTSLIB_HFILE_H

#include <string.h>

#include <sys/types.h>

#include "hts_defs.h"

#ifdef __cplusplus
extern "C" {
#endif

/* These fields are declared here solely for the benefit of the inline functions
   below.  They may change in future releases.  User code should not use them
   directly; you should imagine that hFILE is an opaque incomplete type.  */
struct hFILE_backend;
typedef struct hFILE {
    char *buffer, *begin, *end, *limit;
    const struct hFILE_backend *backend;
    off_t offset;
    int at_eof:1;
    int has_errno;
} hFILE;

hFILE *hopen(const char *filename, const char *mode) HTS_RESULT_USED;

hFILE *hdopen(int fd, const char *mode) HTS_RESULT_USED;

int hclose(hFILE *fp) HTS_RESULT_USED;

void hclose_abruptly(hFILE *fp);

static inline int herrno(hFILE *fp)
{
    return fp->has_errno;
}

static inline void hclearerr(hFILE *fp)
{
    fp->has_errno = 0;
}

off_t hseek(hFILE *fp, off_t offset, int whence) HTS_RESULT_USED;

static inline off_t htell(hFILE *fp)
{
    return fp->offset + (fp->begin - fp->buffer);
}

static inline int hgetc(hFILE *fp)
{
    extern int hgetc2(hFILE *);
    return (fp->end > fp->begin)? (unsigned char) *(fp->begin++) : hgetc2(fp);
}

ssize_t hpeek(hFILE *fp, void *buffer, size_t nbytes) HTS_RESULT_USED;

static inline ssize_t HTS_RESULT_USED
hread(hFILE *fp, void *buffer, size_t nbytes)
{
    extern ssize_t hread2(hFILE *, void *, size_t, size_t);

    size_t n = fp->end - fp->begin;
    if (n > nbytes) n = nbytes;
    memcpy(buffer, fp->begin, n);
    fp->begin += n;
    return (n == nbytes)? (ssize_t) n : hread2(fp, buffer, nbytes, n);
}

static inline int hputc(int c, hFILE *fp)
{
    extern int hputc2(int, hFILE *);
    if (fp->begin < fp->limit) *(fp->begin++) = c;
    else c = hputc2(c, fp);
    return c;
}

static inline int hputs(const char *text, hFILE *fp)
{
    extern int hputs2(const char *, size_t, size_t, hFILE *);

    size_t nbytes = strlen(text), n = fp->limit - fp->begin;
    if (n > nbytes) n = nbytes;
    memcpy(fp->begin, text, n);
    fp->begin += n;
    return (n == nbytes)? 0 : hputs2(text, nbytes, n, fp);
}

static inline ssize_t HTS_RESULT_USED
hwrite(hFILE *fp, const void *buffer, size_t nbytes)
{
    extern ssize_t hwrite2(hFILE *, const void *, size_t, size_t);

    size_t n = fp->limit - fp->begin;
    if (n > nbytes) n = nbytes;
    memcpy(fp->begin, buffer, n);
    fp->begin += n;
    return (n==nbytes)? (ssize_t) n : hwrite2(fp, buffer, nbytes, n);
}

int hflush(hFILE *fp) HTS_RESULT_USED;

#ifdef __cplusplus
}
#endif

#endif