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68895e27d4
janet/src/core/io.c
Calvin Rose 68895e27d4 Change import semantics. Fix gc bug with fibers.
2018-05-18 20:53:19 -04:00

376 lines
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/*
* Copyright (c) 2018 Calvin Rose
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include <dst/dst.h>
#include <dst/dstcorelib.h>
#include <errno.h>
#define IO_WRITE 1
#define IO_READ 2
#define IO_APPEND 4
#define IO_UPDATE 8
#define IO_NOT_CLOSEABLE 16
#define IO_CLOSED 32
#define IO_BINARY 64
#define IO_SERIALIZABLE 128
#define IO_PIPED 256
typedef struct IOFile IOFile;
struct IOFile {
FILE *file;
int flags;
};
static int dst_io_gc(void *p, size_t len);
DstAbstractType dst_io_filetype = {
":core.file",
dst_io_gc,
NULL
};
/* Check argupments to fopen */
static int checkflags(const uint8_t *str, int32_t len) {
int flags = 0;
int32_t i;
if (!len || len > 3) return -1;
switch (*str) {
default:
return -1;
case 'w':
flags |= IO_WRITE;
break;
case 'a':
flags |= IO_APPEND;
break;
case 'r':
flags |= IO_READ;
break;
}
for (i = 1; i < len; i++) {
switch (str[i]) {
default:
return -1;
case '+':
if (flags & IO_UPDATE) return -1;
flags |= IO_UPDATE;
break;
case 'b':
if (flags & IO_BINARY) return -1;
flags |= IO_BINARY;
break;
}
}
return flags;
}
/* Check file argument */
static IOFile *checkfile(DstArgs args, int32_t n) {
IOFile *iof;
if (n >= args.n) {
*args.ret = dst_cstringv("expected core.file");
return NULL;
}
if (!dst_checktype(args.v[n], DST_ABSTRACT)) {
*args.ret = dst_cstringv("expected core.file");
return NULL;
}
iof = (IOFile *) dst_unwrap_abstract(args.v[n]);
if (dst_abstract_type(iof) != &dst_io_filetype) {
*args.ret = dst_cstringv("expected core.file");
return NULL;
}
return iof;
}
/* Check buffer argument */
static DstBuffer *checkbuffer(DstArgs args, int32_t n, int optional) {
if (optional && n == args.n) {
return dst_buffer(0);
}
if (n >= args.n) {
*args.ret = dst_cstringv("expected buffer");
return NULL;
}
if (!dst_checktype(args.v[n], DST_BUFFER)) {
*args.ret = dst_cstringv("expected buffer");
return NULL;
}
return dst_unwrap_abstract(args.v[n]);
}
static Dst makef(FILE *f, int flags) {
IOFile *iof = (IOFile *) dst_abstract(&dst_io_filetype, sizeof(IOFile));
iof->file = f;
iof->flags = flags;
return dst_wrap_abstract(iof);
}
/* Open a process */
static int dst_io_popen(DstArgs args) {
const uint8_t *fname, *fmode;
int32_t modelen;
FILE *f;
int flags;
DST_MINARITY(args, 1);
DST_MAXARITY(args, 2);
DST_ARG_STRING(fname, args, 0);
if (args.n == 2) {
if (!dst_checktype(args.v[1], DST_STRING) &&
!dst_checktype(args.v[1], DST_SYMBOL))
DST_THROW(args, "expected string mode");
fmode = dst_unwrap_string(args.v[1]);
modelen = dst_string_length(fmode);
} else {
fmode = (const uint8_t *)"r";
modelen = 1;
}
if (fmode[0] == ':') {
fmode++;
modelen--;
}
if (modelen != 1 || !(fmode[0] == 'r' || fmode[0] == 'w')) {
DST_THROW(args, "invalid file mode");
}
flags = (fmode[0] == 'r') ? IO_PIPED | IO_READ : IO_PIPED | IO_WRITE;
#ifdef DST_WINDOWS
f = _popen((const char *)fname, (const char *)fmode);
#else
f = popen((const char *)fname, (const char *)fmode);
#endif
if (!f) {
if (errno == EMFILE) {
DST_THROW(args, "too many streams are open");
}
DST_THROW(args, "could not open file");
}
DST_RETURN(args, makef(f, flags));
}
/* Open a a file and return a userdata wrapper around the C file API. */
static int dst_io_fopen(DstArgs args) {
const uint8_t *fname, *fmode;
int32_t modelen;
FILE *f;
int flags;
DST_MINARITY(args, 1);
DST_MAXARITY(args, 2);
DST_ARG_STRING(fname, args, 0);
if (args.n == 2) {
if (!dst_checktype(args.v[1], DST_STRING) &&
!dst_checktype(args.v[1], DST_SYMBOL))
DST_THROW(args, "expected string mode");
fmode = dst_unwrap_string(args.v[1]);
modelen = dst_string_length(fmode);
} else {
fmode = (const uint8_t *)"r";
modelen = 1;
}
if (fmode[0] == ':') {
fmode++;
modelen--;
}
if ((flags = checkflags(fmode, modelen)) < 0) {
DST_THROW(args, "invalid file mode");
}
f = fopen((const char *)fname, (const char *)fmode);
DST_RETURN(args, f ? makef(f, flags) : dst_wrap_nil());
}
/* Read a certain number of bytes into memory */
static int dst_io_fread(DstArgs args) {
DstBuffer *b;
int32_t len;
size_t ntoread, nread;
IOFile *iof = checkfile(args, 0);
if (!iof) return 1;
if (iof->flags & IO_CLOSED)
DST_THROW(args, "file is closed");
b = checkbuffer(args, 2, 1);
if (!b) return 1;
if (dst_checktype(args.v[1], DST_SYMBOL)) {
const uint8_t *sym = dst_unwrap_symbol(args.v[1]);
if (!dst_cstrcmp(sym, ":all")) {
/* Read whole file */
long fsize;
fseek(iof->file, 0, SEEK_END);
fsize = ftell(iof->file);
fseek(iof->file, 0, SEEK_SET);
if (fsize > INT32_MAX) DST_THROW(args, "buffer overflow");
len = fsize;
/* Fall through to normal code */
} else if (!dst_cstrcmp(sym, ":line")) {
for (;;) {
int x = fgetc(iof->file);
if (x != EOF && dst_buffer_push_u8(b, (uint8_t)x))
DST_THROW(args, "buffer overflow");
if (x == EOF || x == '\n') break;
}
DST_RETURN(args, dst_wrap_buffer(b));
} else {
DST_THROW(args, "expected one of :all, :line");
}
} else if (!dst_checktype(args.v[1], DST_INTEGER)) {
DST_THROW(args, "expected positive integer");
} else {
len = dst_unwrap_integer(args.v[1]);
if (len < 0) DST_THROW(args, "expected positive integer");
}
if (!(iof->flags & (IO_READ | IO_UPDATE))) DST_THROW(args, "file is not readable");
/* Ensure buffer size */
if (dst_buffer_extra(b, len)) DST_THROW(args, "buffer overflow");
ntoread = len;
nread = fread((char *)(b->data + b->count), 1, ntoread, iof->file);
if (nread != ntoread && ferror(iof->file)) DST_THROW(args, "could not read file");
b->count += nread;
DST_RETURN(args, dst_wrap_buffer(b));
}
/* Write bytes to a file */
static int dst_io_fwrite(DstArgs args) {
int32_t len, i;
const uint8_t *str;
IOFile *iof = checkfile(args, 0);
if (!iof) return 1;
if (iof->flags & IO_CLOSED)
DST_THROW(args, "file is closed");
if (!(iof->flags & (IO_WRITE | IO_APPEND | IO_UPDATE)))
DST_THROW(args, "file is not writeable");
for (i = 1; i < args.n; i++) {
DST_CHECKMANY(args, i, DST_TFLAG_BYTES);
}
for (i = 1; i < args.n; i++) {
DST_ARG_BYTES(str, len, args, i);
if (len) {
if (!fwrite(str, len, 1, iof->file)) DST_THROW(args, "error writing to file");
}
}
DST_RETURN(args, dst_wrap_abstract(iof));
}
/* Flush the bytes in the file */
static int dst_io_fflush(DstArgs args) {
IOFile *iof = checkfile(args, 0);
if (!iof) return 1;
if (iof->flags & IO_CLOSED)
DST_THROW(args, "file is closed");
if (!(iof->flags & (IO_WRITE | IO_APPEND | IO_UPDATE)))
DST_THROW(args, "file is not flushable");
if (fflush(iof->file)) DST_THROW(args, "could not flush file");
DST_RETURN(args, dst_wrap_abstract(iof));
}
/* Cleanup a file */
static int dst_io_gc(void *p, size_t len) {
(void) len;
IOFile *iof = (IOFile *)p;
if (!(iof->flags & (IO_NOT_CLOSEABLE | IO_CLOSED))) {
return fclose(iof->file);
}
return 0;
}
/* Close a file */
static int dst_io_fclose(DstArgs args) {
IOFile *iof = checkfile(args, 0);
if (!iof) return 1;
if (iof->flags & (IO_CLOSED))
DST_THROW(args, "file already closed");
if (iof->flags & (IO_NOT_CLOSEABLE))
DST_THROW(args, "file not closable");
if (iof->flags & IO_PIPED) {
#ifdef DST_WINDOWS
if (_pclose(iof->file)) DST_THROW(args, "could not close file");
#else
if (pclose(iof->file)) DST_THROW(args, "could not close file");
#endif
} else {
if (fclose(iof->file)) DST_THROW(args, "could not close file");
}
iof->flags |= IO_CLOSED;
DST_RETURN(args, dst_wrap_abstract(iof));
}
/* Seek a file */
static int dst_io_fseek(DstArgs args) {
long int offset = 0;
int whence = SEEK_CUR;
IOFile *iof = checkfile(args, 0);
if (!iof) return 1;
if (iof->flags & IO_CLOSED)
DST_THROW(args, "file is closed");
if (args.n >= 2) {
const uint8_t *whence_sym;
if (!dst_checktype(args.v[1], DST_SYMBOL))
DST_THROW(args, "expected symbol");
whence_sym = dst_unwrap_symbol(args.v[1]);
if (!dst_cstrcmp(whence_sym, ":cur")) {
whence = SEEK_CUR;
} else if (!dst_cstrcmp(whence_sym, ":set")) {
whence = SEEK_SET;
} else if (!dst_cstrcmp(whence_sym, ":end")) {
whence = SEEK_END;
} else {
DST_THROW(args, "expected one of :cur, :set, :end");
}
if (args.n >= 3) {
if (!dst_checktype(args.v[2], DST_INTEGER))
DST_THROW(args, "expected integer");
offset = dst_unwrap_integer(args.v[2]);
}
}
if (fseek(iof->file, offset, whence))
DST_THROW(args, "error seeking file");
DST_RETURN(args, args.v[0]);
}
static const DstReg cfuns[] = {
{"file.open", dst_io_fopen},
{"file.close", dst_io_fclose},
{"file.read", dst_io_fread},
{"file.write", dst_io_fwrite},
{"file.flush", dst_io_fflush},
{"file.seek", dst_io_fseek},
{"file.popen", dst_io_popen},
{NULL, NULL}
};
/* Module entry point */
int dst_lib_io(DstArgs args) {
DstTable *env = dst_env_arg(args);
dst_env_cfuns(env, cfuns);
/* stdout */
dst_env_def(env, "stdout",
makef(stdout, IO_APPEND | IO_NOT_CLOSEABLE | IO_SERIALIZABLE));
/* stderr */
dst_env_def(env, "stderr",
makef(stderr, IO_APPEND | IO_NOT_CLOSEABLE | IO_SERIALIZABLE));
/* stdin */
dst_env_def(env, "stdin",
makef(stdin, IO_READ | IO_NOT_CLOSEABLE | IO_SERIALIZABLE));
return 0;
}
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