diff options
author | Jörg Frings-Fürst <debian@jff-webhosting.net> | 2015-11-06 05:38:49 +0100 |
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committer | Jörg Frings-Fürst <debian@jff-webhosting.net> | 2015-11-06 05:38:49 +0100 |
commit | 9491825ddff7a294d1f49061bae7044e426aeb2e (patch) | |
tree | 06e651099f87140ec534ae47fb8ce1ac6ec7976d /tiff/contrib/mfs/mfs_file.c | |
parent | fa756339d4204bff7f2820067f58214d32780d17 (diff) |
Imported Upstream version 1.8.3
Diffstat (limited to 'tiff/contrib/mfs/mfs_file.c')
-rwxr-xr-x | tiff/contrib/mfs/mfs_file.c | 586 |
1 files changed, 586 insertions, 0 deletions
diff --git a/tiff/contrib/mfs/mfs_file.c b/tiff/contrib/mfs/mfs_file.c new file mode 100755 index 0000000..6675e2a --- /dev/null +++ b/tiff/contrib/mfs/mfs_file.c @@ -0,0 +1,586 @@ +/* +-------------------------------------------------------------------------------- +- Module : mem_file.c +- Description : A general purpose library for manipulating a memory area +- as if it were a file. +- mfs_ stands for memory file system. +- Author : Mike Johnson - Banctec AB 03/07/96 +- +-------------------------------------------------------------------------------- +*/ + +/* + +Copyright (c) 1996 Mike Johnson +Copyright (c) 1996 BancTec AB + +Permission to use, copy, modify, distribute, and sell this software +for any purpose is hereby granted without fee, provided +that (i) the above copyright notices and this permission notice appear in +all copies of the software and related documentation, and (ii) the names of +Mike Johnson and BancTec may not be used in any advertising or +publicity relating to the software. + +THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, +EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY +WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + +IN NO EVENT SHALL MIKE JOHNSON OR BANCTEC BE LIABLE FOR +ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, +OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, +WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF +LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE +OF THIS SOFTWARE. + +*/ + + +/* +-------------------------------------------------------------------------------- +- Includes +-------------------------------------------------------------------------------- +*/ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +/* +-------------------------------------------------------------------------------- +- Definitions +-------------------------------------------------------------------------------- +*/ + +#define MAX_BUFFS 20 +#define FALSE 0 +#define TRUE 1 + +/* +-------------------------------------------------------------------------------- +- Globals +-------------------------------------------------------------------------------- +*/ + +static char *buf[MAX_BUFFS]; /* Memory for each open buf */ +static long buf_off[MAX_BUFFS]; /* File pointer for each buf */ +static long buf_size[MAX_BUFFS]; /* Count of bytes allocated for each buf */ +static long fds[MAX_BUFFS]; /* File descriptor status */ +static int buf_mode[MAX_BUFFS]; /* Mode of buffer (r, w, a) */ + +static int library_init_done = FALSE; + + +/* +-------------------------------------------------------------------------------- +- Function prototypes +-------------------------------------------------------------------------------- +*/ + +int mfs_open (void *ptr, int size, char *mode); +int mfs_lseek (int fd, int offset, int whence); +int mfs_read (int fd, void *buf, int size); +int mfs_write (int fd, void *buf, int size); +int mfs_size (int fd); +int mfs_map (int fd, char **addr, size_t *len); +int mfs_unmap (int fd); +int mfs_close (int fd); +static int extend_mem_file (int fd, int size); +static void mem_init (); + +/* +-------------------------------------------------------------------------------- +- Function code +-------------------------------------------------------------------------------- +*/ + +/* +-------------------------------------------------------------------------------- +- Function : mfs_open () +- +- Arguments : Pointer to allocated buffer, initial size of buffer, +- mode spec (r, w, a) +- +- Returns : File descriptor or -1 if error. +- +- Description : Register this area of memory (which has been allocated +- and has a file read into it) under the mem_file library. +- A file descriptor is returned which can the be passed +- back to TIFFClientOpen and used as if it was a disk +- based fd. +- If the call is for mode 'w' then pass (void *)NULL as +- the buffer and zero size and the library will +- allocate memory for you. +- If the mode is append then pass (void *)NULL and size +- zero or with a valid address. +- +-------------------------------------------------------------------------------- +*/ + +int mfs_open (void *buffer, int size, char *mode) +{ + int ret, i; + void *tmp; + + if (library_init_done == FALSE) + { + mem_init (); + library_init_done = TRUE; + } + + ret = -1; + + /* Find a free fd */ + + for (i = 0; i < MAX_BUFFS; i++) + { + if (fds[i] == -1) + { + ret = i; + break; + } + } + + if (i == MAX_BUFFS) /* No more free descriptors */ + { + ret = -1; + errno = EMFILE; + } + + if (ret >= 0 && *mode == 'r') + { + if (buffer == (void *)NULL) + { + ret = -1; + errno = EINVAL; + } + else + { + buf[ret] = (char *)buffer; + buf_size[ret] = size; + buf_off[ret] = 0; + } + } + else if (ret >= 0 && *mode == 'w') + { + + if (buffer != (void *)NULL) + { + ret = -1; + errno = EINVAL; + } + + else + { + tmp = malloc (0); /* Get a pointer */ + if (tmp == (void *)NULL) + { + ret = -1; + errno = EDQUOT; + } + else + { + buf[ret] = (char *)tmp; + buf_size[ret] = 0; + buf_off[ret] = 0; + } + } + } + else if (ret >= 0 && *mode == 'a') + { + if (buffer == (void *) NULL) /* Create space for client */ + { + tmp = malloc (0); /* Get a pointer */ + if (tmp == (void *)NULL) + { + ret = -1; + errno = EDQUOT; + } + else + { + buf[ret] = (char *)tmp; + buf_size[ret] = 0; + buf_off[ret] = 0; + } + } + else /* Client has file read in already */ + { + buf[ret] = (char *)buffer; + buf_size[ret] = size; + buf_off[ret] = 0; + } + } + else /* Some other invalid combination of parameters */ + { + ret = -1; + errno = EINVAL; + } + + if (ret != -1) + { + fds[ret] = 0; + buf_mode[ret] = *mode; + } + + return (ret); +} + +/* +-------------------------------------------------------------------------------- +- Function : mfs_lseek () +- +- Arguments : File descriptor, offset, whence +- +- Returns : as per man lseek (2) +- +- Description : Does the same as lseek (2) except on a memory based file. +- Note: the memory area will be extended if the caller +- attempts to seek past the current end of file (memory). +- +-------------------------------------------------------------------------------- +*/ + +int mfs_lseek (int fd, int offset, int whence) +{ + int ret; + long test_off; + + if (fds[fd] == -1) /* Not open */ + { + ret = -1; + errno = EBADF; + } + else if (offset < 0 && whence == SEEK_SET) + { + ret = -1; + errno = EINVAL; + } + else + { + switch (whence) + { + case SEEK_SET: + if (offset > buf_size[fd]) + extend_mem_file (fd, offset); + buf_off[fd] = offset; + ret = offset; + break; + + case SEEK_CUR: + test_off = buf_off[fd] + offset; + + if (test_off < 0) + { + ret = -1; + errno = EINVAL; + } + else + { + if (test_off > buf_size[fd]) + extend_mem_file (fd, test_off); + buf_off[fd] = test_off; + ret = test_off; + } + break; + + case SEEK_END: + test_off = buf_size[fd] + offset; + + if (test_off < 0) + { + ret = -1; + errno = EINVAL; + } + else + { + if (test_off > buf_size[fd]) + extend_mem_file (fd, test_off); + buf_off[fd] = test_off; + ret = test_off; + } + break; + + default: + errno = EINVAL; + ret = -1; + break; + } + } + + return (ret); +} + +/* +-------------------------------------------------------------------------------- +- Function : mfs_read () +- +- Arguments : File descriptor, buffer, size +- +- Returns : as per man read (2) +- +- Description : Does the same as read (2) except on a memory based file. +- Note: An attempt to read past the end of memory currently +- allocated to the file will return 0 (End Of File) +- +-------------------------------------------------------------------------------- +*/ + +int mfs_read (int fd, void *clnt_buf, int size) +{ + int ret; + + if (fds[fd] == -1 || buf_mode[fd] != 'r') + { + /* File is either not open, or not opened for read */ + + ret = -1; + errno = EBADF; + } + else if (buf_off[fd] + size > buf_size[fd]) + { + ret = 0; /* EOF */ + } + else + { + memcpy (clnt_buf, (void *) (buf[fd] + buf_off[fd]), size); + buf_off[fd] = buf_off[fd] + size; + ret = size; + } + + return (ret); +} + +/* +-------------------------------------------------------------------------------- +- Function : mfs_write () +- +- Arguments : File descriptor, buffer, size +- +- Returns : as per man write (2) +- +- Description : Does the same as write (2) except on a memory based file. +- Note: the memory area will be extended if the caller +- attempts to write past the current end of file (memory). +- +-------------------------------------------------------------------------------- +*/ + +int mfs_write (int fd, void *clnt_buf, int size) +{ + int ret; + + if (fds[fd] == -1 || buf_mode[fd] == 'r') + { + /* Either the file is not open or it is opened for reading only */ + + ret = -1; + errno = EBADF; + } + else if (buf_mode[fd] == 'w') + { + /* Write */ + + if (buf_off[fd] + size > buf_size[fd]) + { + extend_mem_file (fd, buf_off[fd] + size); + buf_size[fd] = (buf_off[fd] + size); + } + + memcpy ((buf[fd] + buf_off[fd]), clnt_buf, size); + buf_off[fd] = buf_off[fd] + size; + + ret = size; + } + else + { + /* Append */ + + if (buf_off[fd] != buf_size[fd]) + buf_off[fd] = buf_size[fd]; + + extend_mem_file (fd, buf_off[fd] + size); + buf_size[fd] += size; + + memcpy ((buf[fd] + buf_off[fd]), clnt_buf, size); + buf_off[fd] = buf_off[fd] + size; + + ret = size; + } + + return (ret); +} + +/* +-------------------------------------------------------------------------------- +- Function : mfs_size () +- +- Arguments : File descriptor +- +- Returns : integer file size +- +- Description : This function returns the current size of the file in bytes. +- +-------------------------------------------------------------------------------- +*/ + +int mfs_size (int fd) +{ + int ret; + + if (fds[fd] == -1) /* Not open */ + { + ret = -1; + errno = EBADF; + } + else + ret = buf_size[fd]; + + return (ret); +} + +/* +-------------------------------------------------------------------------------- +- Function : mfs_map () +- +- Arguments : File descriptor, ptr to address, ptr to length +- +- Returns : Map status (succeeded or otherwise) +- +- Description : This function tells the client where the file is mapped +- in memory and what size the mapped area is. It is provided +- to satisfy the MapProc function in libtiff. It pretends +- that the file has been mmap (2)ped. +- +-------------------------------------------------------------------------------- +*/ + +int mfs_map (int fd, char **addr, size_t *len) +{ + int ret; + + if (fds[fd] == -1) /* Not open */ + { + ret = -1; + errno = EBADF; + } + else + { + *addr = buf[fd]; + *len = buf_size[fd]; + ret = 0; + } + + return (ret); +} + +/* +-------------------------------------------------------------------------------- +- Function : mfs_unmap () +- +- Arguments : File descriptor +- +- Returns : UnMap status (succeeded or otherwise) +- +- Description : This function does nothing as the file is always +- in memory. +- +-------------------------------------------------------------------------------- +*/ + +int mfs_unmap (int fd) +{ + return (0); +} + +/* +-------------------------------------------------------------------------------- +- Function : mfs_close () +- +- Arguments : File descriptor +- +- Returns : close status (succeeded or otherwise) +- +- Description : Close the open memory file. (Make fd available again.) +- +-------------------------------------------------------------------------------- +*/ + +int mfs_close (int fd) +{ + int ret; + + if (fds[fd] == -1) /* Not open */ + { + ret = -1; + errno = EBADF; + } + else + { + fds[fd] = -1; + ret = 0; + } + + return (ret); +} + +/* +-------------------------------------------------------------------------------- +- Function : extend_mem_file () +- +- Arguments : File descriptor, length to extend to. +- +- Returns : 0 - All OK, -1 - realloc () failed. +- +- Description : Increase the amount of memory allocated to a file. +- +-------------------------------------------------------------------------------- +*/ + +static int extend_mem_file (int fd, int size) +{ + void *new_mem; + int ret; + + if ((new_mem = realloc (buf[fd], size)) == (void *) NULL) + ret = -1; + else + { + buf[fd] = (char *) new_mem; + ret = 0; + } + + return (ret); +} + +/* +-------------------------------------------------------------------------------- +- Function : mem_init () +- +- Arguments : None +- +- Returns : void +- +- Description : Initialise the library. +- +-------------------------------------------------------------------------------- +*/ + +static void mem_init () +{ + int i; + + for (i = 0; i < MAX_BUFFS; i++) + { + fds[i] = -1; + buf[i] = (char *)NULL; + buf_size[i] = 0; + buf_off[i] = 0; + } +} + +/* + * Local Variables: + * mode: c + * c-basic-offset: 8 + * fill-column: 78 + * End: + */ |