diff options
Diffstat (limited to 'otherlibs/bigarray/mmap_unix.c')
| -rw-r--r-- | otherlibs/bigarray/mmap_unix.c | 44 |
1 files changed, 31 insertions, 13 deletions
diff --git a/otherlibs/bigarray/mmap_unix.c b/otherlibs/bigarray/mmap_unix.c index 3b5ffd1ce..0acef2004 100644 --- a/otherlibs/bigarray/mmap_unix.c +++ b/otherlibs/bigarray/mmap_unix.c @@ -18,6 +18,7 @@ #include "bigarray.h" #include "custom.h" #include "fail.h" +#include "io.h" #include "mlvalues.h" #include "sys.h" @@ -38,18 +39,19 @@ extern int caml_ba_element_size[]; /* from bigarray_stubs.c */ #endif CAMLprim value caml_ba_map_file(value vfd, value vkind, value vlayout, - value vshared, value vdim) + value vshared, value vdim, value vstart) { int fd, flags, major_dim, shared; intnat num_dims, i; intnat dim[MAX_NUM_DIMS]; - intnat currpos, file_size; - uintnat array_size; + file_offset currpos, startpos, file_size, data_size; + uintnat array_size, page, delta; char c; void * addr; fd = Int_val(vfd); flags = Int_val(vkind) | Int_val(vlayout); + startpos = File_offset_val(vstart); num_dims = Wosize_val(vdim); major_dim = flags & BIGARRAY_FORTRAN_LAYOUT ? num_dims - 1 : 0; /* Extract dimensions from Caml array */ @@ -72,27 +74,36 @@ CAMLprim value caml_ba_map_file(value vfd, value vkind, value vlayout, array_size = bigarray_element_size[flags & BIGARRAY_KIND_MASK]; for (i = 0; i < num_dims; i++) if (dim[i] != -1) array_size *= dim[i]; - /* Check if the first/last dimension is unknown */ + /* Check if the major dimension is unknown */ if (dim[major_dim] == -1) { - /* Determine first/last dimension from file size */ - if ((uintnat) file_size % array_size != 0) + /* Determine major dimension from file size */ + if (file_size < startpos) + failwith("Bigarray.mmap: file position exceeds file size"); + data_size = file_size - startpos; + dim[major_dim] = (uintnat) (data_size / array_size); + array_size = dim[major_dim] * array_size; + if (array_size != data_size) failwith("Bigarray.mmap: file size doesn't match array dimensions"); - dim[major_dim] = (uintnat) file_size / array_size; - array_size = file_size; } else { /* Check that file is large enough, and grow it otherwise */ - if (file_size < array_size) { - if (lseek(fd, array_size - 1, SEEK_SET) == -1) sys_error(NO_ARG); + if (file_size < startpos + array_size) { + if (lseek(fd, startpos + array_size - 1, SEEK_SET) == -1) + sys_error(NO_ARG); c = 0; if (write(fd, &c, 1) != 1) sys_error(NO_ARG); } } /* Restore original file position */ lseek(fd, currpos, SEEK_SET); + /* Determine offset so that the mapping starts at the given file pos */ + page = getpagesize(); + delta = (uintnat) (startpos % page); /* Do the mmap */ shared = Bool_val(vshared) ? MAP_SHARED : MAP_PRIVATE; - addr = mmap(NULL, array_size, PROT_READ | PROT_WRITE, shared, fd, 0); + addr = mmap(NULL, array_size + delta, PROT_READ | PROT_WRITE, + shared, fd, startpos - delta); if (addr == (void *) MAP_FAILED) sys_error(NO_ARG); + addr = (void *) ((uintnat) addr + delta); /* Build and return the Caml bigarray */ return alloc_bigarray(flags | BIGARRAY_MAPPED_FILE, num_dims, addr, dim); } @@ -100,7 +111,7 @@ CAMLprim value caml_ba_map_file(value vfd, value vkind, value vlayout, #else value caml_ba_map_file(value vfd, value vkind, value vlayout, - value vshared, value vdim) + value vshared, value vdim, value vpos) { invalid_argument("Bigarray.map_file: not supported"); return Val_unit; @@ -108,10 +119,17 @@ value caml_ba_map_file(value vfd, value vkind, value vlayout, #endif +CAMLprim value caml_ba_map_file_bytecode(value * argv, int argn) +{ + return caml_ba_map_file(argv[0], argv[1], argv[2], + argv[3], argv[4], argv[5]); +} void caml_ba_unmap_file(void * addr, uintnat len) { #if defined(HAS_MMAP) - munmap(addr, len); + uintnat page = getpagesize(); + uintnat delta = (uintnat) addr % page; + munmap((void *)((uintnat)addr - delta), len + delta); #endif } |