NAME ^

src/io/io_mmap.c - IO Layer for mmaped files

DESCRIPTION ^

Open mmaps the file.

mmap layer functions ^

*/

#include "parrot/parrot.h" #include "io_private.h"

/* HEADERIZER HFILE: none */

/* HEADERIZER BEGIN: static */

static INTVAL PIO_mmap_close( PARROT_INTERP, NOTNULL(ParrotIOLayer *layer), NOTNULL(ParrotIO *io) ) __attribute__nonnull__(1) __attribute__nonnull__(2) __attribute__nonnull__(3);

PARROT_WARN_UNUSED_RESULT PARROT_CAN_RETURN_NULL static ParrotIO * PIO_mmap_open( PARROT_INTERP, NOTNULL(ParrotIOLayer *layer), NOTNULL(const char *path), INTVAL flags ) __attribute__nonnull__(1) __attribute__nonnull__(2) __attribute__nonnull__(3);

static size_t PIO_mmap_read( PARROT_INTERP, NOTNULL(ParrotIOLayer *layer), NOTNULL(ParrotIO *io), NOTNULL(STRING **buf) ) __attribute__nonnull__(1) __attribute__nonnull__(2) __attribute__nonnull__(3) __attribute__nonnull__(4);

/* HEADERIZER END: static */

static const ParrotIOLayerAPI pio_mmap_layer_api = { PIO_null_init, PIO_base_new_layer, PIO_base_delete_layer, PIO_null_push_layer, PIO_null_pop_layer, PIO_mmap_open, PIO_null_open2, PIO_null_open3, PIO_null_open_async, PIO_null_fdopen, PIO_mmap_close, PIO_null_write, PIO_null_write_async, PIO_mmap_read, PIO_null_read_async, PIO_null_flush, PIO_null_peek, PIO_null_seek, PIO_null_tell, PIO_null_setbuf, PIO_null_setlinebuf, PIO_null_getcount, PIO_null_fill, PIO_null_eof, NULL, /* no poll */ NULL, /* no socket */ NULL, /* no connect */ NULL, /* no send */ NULL, /* no recv */ NULL, /* no bind */ NULL, /* no listen */ NULL /* no accept */ };

ParrotIOLayer pio_mmap_layer = { NULL, "mmap", 0, &pio_mmap_layer_api, NULL, NULL };

PARROT_WARN_UNUSED_RESULT PARROT_CANNOT_RETURN_NULL ParrotIOLayer * PIO_mmap_register_layer(void) { return &pio_mmap_layer; }

/*

FUNCDOC: PIO_mmap_open

The buffer layer's Open function.

*/

PARROT_WARN_UNUSED_RESULT PARROT_CAN_RETURN_NULL static ParrotIO * PIO_mmap_open(PARROT_INTERP, NOTNULL(ParrotIOLayer *layer), NOTNULL(const char *path), INTVAL flags) { ParrotIO *io; ParrotIOLayer *l = PIO_DOWNLAYER(layer);

    if (!l) {
        l = interp->piodata->default_stack;
        if (strcmp(l->name, "buf") == 0)
            l = PIO_DOWNLAYER(l);
    }
    io = PIO_open_down(interp, l, path, flags);
    if (!io) {
        /* error creating IO stream */
        return NULL;
    }
#ifdef PARROT_HAS_HEADER_SYSMMAN
    {
        /* XXX assume fstat exists too
        */
        struct stat statbuf;
        int status;
        PIOOFF_T file_size;

        status = fstat(io->fd, &statbuf); /* XXX We're ignoring this return value. */
        file_size = statbuf.st_size;
        /* TODO verify flags */
        io->b.startb = (unsigned char *)mmap(0, file_size, PROT_READ, MAP_SHARED, io->fd, 0);
        io->b.size = (size_t)file_size;  /* XXX */
        io->b.endb = io->b.startb + io->b.size;
        io->b.flags |= PIO_BF_MMAP;
    }
#endif
    return io;
}

/*

FUNCDOC: PIO_mmap_read

Calls read() to return up to len bytes in the memory starting at buffer.

*/

static size_t PIO_mmap_read(PARROT_INTERP, NOTNULL(ParrotIOLayer *layer), NOTNULL(ParrotIO *io), NOTNULL(STRING **buf)) { STRING *s; UINTVAL len;

    if (!(io->b.flags & PIO_BF_MMAP))
        return PIO_read_down(interp, PIO_DOWNLAYER(layer), io, buf);

    if (*buf == NULL) {
        *buf = new_string_header(interp, 0);
    }
    s = *buf;
    /* TODO create string_free API for reusing string headers */
    if (s->strstart && PObj_sysmem_TEST(s))
        mem_sys_free(PObj_bufstart(s));
    PObj_get_FLAGS(s) |= PObj_external_FLAG;
    PObj_bufstart(s) = io->b.startb + io->fpos;
    s->strstart =  (char *) io->b.startb + io->fpos;
    len = s->bufused ? s->bufused : io->b.size;
    io->fpos += len;
    PObj_buflen(s) = s->strlen = len;
    return len;
}

/*

FUNCDOC: PIO_mmap_close

Closes *io's file descriptor.

*/

static INTVAL PIO_mmap_close(PARROT_INTERP, NOTNULL(ParrotIOLayer *layer), NOTNULL(ParrotIO *io)) { INTVAL ret = -1;

    if (io->fd >= 0)
        ret = PIO_close_down(interp, PIO_DOWNLAYER(layer), io);
    return ret;
}

/*

SEE ALSO ^

src/io/io_passdown.c, src/io/io.c, src/io/io_layers.c, src/io/io_private.h.

HISTORY ^

Initially written by Leo.

*/

/* * Local variables: * c-file-style: "parrot" * End: * vim: expandtab shiftwidth=4: */


 parrot