kevin/neovim
1
Fork 0
mirror of https://github.com/neovim/neovim.git synced 2024-12-20 03:05:11 -07:00
Code Issues Packages Projects Releases Wiki Activity

os/fileio: Use readv often

Browse Source
This commit is contained in:
ZyX 2016-06-24 01:07:09 +03:00
parent 6580dfeddd
commit 96a57e1bc6
1 changed files with 23 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
src/nvim/os/fileio.c
View File

@ -216,30 +216,31 @@ ptrdiff_t file_read(FileDescriptor *const fp, char *const ret_buf,
if (read_remaining) {
assert(rbuffer_size(rv) == 0);
rbuffer_reset(rv);
if (read_remaining >= kRWBufferSize) {
#ifdef HAVE_READV
// If there is readv() syscall, then take an opportunity to populate
// both target buffer and RBuffer at once, …
size_t write_count;
struct iovec iov[] = {
{ .iov_base = buf, .iov_len = read_remaining },
{ .iov_base = rbuffer_write_ptr(rv, &write_count),
.iov_len = kRWBufferSize },
};
assert(write_count == kRWBufferSize);
const ptrdiff_t r_ret = os_readv(fp->fd, &fp->eof, iov,
ARRAY_SIZE(iov));
if (r_ret > 0) {
if (r_ret > (ptrdiff_t)read_remaining) {
read_remaining = 0;
rbuffer_produced(rv, (size_t)(r_ret - (ptrdiff_t)read_remaining));
} else {
read_remaining -= (size_t)r_ret;
}
} else if (r_ret < 0) {
return r_ret;
// If there is readv() syscall, then take an opportunity to populate
// both target buffer and RBuffer at once, …
size_t write_count;
struct iovec iov[] = {
{ .iov_base = buf, .iov_len = read_remaining },
{ .iov_base = rbuffer_write_ptr(rv, &write_count),
.iov_len = kRWBufferSize },
};
assert(write_count == kRWBufferSize);
const ptrdiff_t r_ret = os_readv(fp->fd, &fp->eof, iov,
ARRAY_SIZE(iov));
if (r_ret > 0) {
if (r_ret > (ptrdiff_t)read_remaining) {
rbuffer_produced(rv, (size_t)(r_ret - (ptrdiff_t)read_remaining));
read_remaining = 0;
} else {
buf += (size_t)r_ret;
read_remaining -= (size_t)r_ret;
}
} else if (r_ret < 0) {
return r_ret;
}
#else
if (read_remaining >= kRWBufferSize) {
// …otherwise leave RBuffer empty and populate only target buffer,
// because filtering information through rbuffer will be more syscalls.
const ptrdiff_t r_ret = os_read(fp->fd, &fp->eof, buf, read_remaining);
@ -249,7 +250,6 @@ ptrdiff_t file_read(FileDescriptor *const fp, char *const ret_buf,
} else if (r_ret < 0) {
return r_ret;
}
#endif
} else {
size_t write_count;
const ptrdiff_t r_ret = os_read(fp->fd, &fp->eof,
@ -262,6 +262,7 @@ ptrdiff_t file_read(FileDescriptor *const fp, char *const ret_buf,
return r_ret;
}
}
#endif
}
}
return (ptrdiff_t)(size - read_remaining);