diff options
author | Nicholas Noll <nnoll523@gmail.com> | 2021-10-23 11:17:25 -0700 |
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committer | Nicholas Noll <nnoll523@gmail.com> | 2021-10-26 11:11:57 -0700 |
commit | c8e1e71eb526475dd431443345262c2e5a627831 (patch) | |
tree | ea9f7bcbba18a13f7ba8b32fcb1433ac2f4dd8b4 /sys/base/mmap.c | |
parent | 40f4c7305a041d4214df117491593898d04d0134 (diff) |
chore(rename): libn -> base
Diffstat (limited to 'sys/base/mmap.c')
-rw-r--r-- | sys/base/mmap.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/sys/base/mmap.c b/sys/base/mmap.c new file mode 100644 index 0000000..6edfe28 --- /dev/null +++ b/sys/base/mmap.c @@ -0,0 +1,43 @@ +#include <u.h> +#include <base.h> + +#include <sys/mman.h> + +mmap·Reader +mmap·open(byte *filename) +{ + int fd; + int err; + void *buf; + io·Stream *s; + io·Stat st; + + s = io·open(filename, "r"); + fd = io·fd(s); + err = io·stat(s, &st); + if (err) { + errorf("file stat: error code %d", err); + goto ERROR; + } + + buf = mmap(nil, st.st_size, PROT_READ, MAP_SHARED, fd, 0); + if (!buf) { + errorf("mmap: failed"); + goto ERROR; + } + // NOTE: posix systems require that reference kept to mmap file after fd is closed + io·close(s); + return (mmap·Reader){.len=st.st_size, .buf=buf}; + +ERROR: + io·close(s); + return (mmap·Reader){ 0 }; +} + +error +mmap·close(mmap·Reader rdr) +{ + munmap(rdr.buf, rdr.len); + + return 0; +} |