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/* reader.c
* Copyright (c) 2011, Peter Ohler
* All rights reserved.
*/
#include <stdlib.h>
#include <errno.h>
#include <stdio.h>
#include <strings.h>
#include <sys/types.h>
#if NEEDS_UIO
#include <sys/uio.h>
#endif
#include <unistd.h>
#include <time.h>
#include "ruby.h"
#include "oj.h"
#include "reader.h"
#define BUF_PAD 4
static VALUE rescue_cb(VALUE rdr, VALUE err);
static VALUE io_cb(VALUE rdr);
static VALUE partial_io_cb(VALUE rdr);
static int read_from_io(Reader reader);
static int read_from_fd(Reader reader);
static int read_from_io_partial(Reader reader);
//static int read_from_str(Reader reader);
void
oj_reader_init(Reader reader, VALUE io, int fd, bool to_s) {
VALUE io_class = rb_obj_class(io);
VALUE stat;
VALUE ftype;
reader->head = reader->base;
*((char*)reader->head) = '\0';
reader->end = reader->head + sizeof(reader->base) - BUF_PAD;
reader->tail = reader->head;
reader->read_end = reader->head;
reader->pro = 0;
reader->str = 0;
reader->pos = 0;
reader->line = 1;
reader->col = 0;
reader->free_head = 0;
if (0 != fd) {
reader->read_func = read_from_fd;
reader->fd = fd;
} else if (rb_cString == io_class) {
reader->read_func = 0;
reader->in_str = StringValuePtr(io);
reader->head = (char*)reader->in_str;
reader->tail = reader->head;
reader->read_end = reader->head + RSTRING_LEN(io);
} else if (oj_stringio_class == io_class) {
VALUE s = rb_funcall2(io, oj_string_id, 0, 0);
reader->read_func = 0;
reader->in_str = StringValuePtr(s);
reader->head = (char*)reader->in_str;
reader->tail = reader->head;
reader->read_end = reader->head + RSTRING_LEN(s);
} else if (rb_cFile == io_class &&
Qnil != (stat = rb_funcall(io, oj_stat_id, 0)) &&
Qnil != (ftype = rb_funcall(stat, oj_ftype_id, 0)) &&
0 == strcmp("file", StringValuePtr(ftype)) &&
0 == FIX2INT(rb_funcall(io, oj_pos_id, 0))) {
reader->read_func = read_from_fd;
reader->fd = FIX2INT(rb_funcall(io, oj_fileno_id, 0));
} else if (rb_respond_to(io, oj_readpartial_id)) {
reader->read_func = read_from_io_partial;
reader->io = io;
} else if (rb_respond_to(io, oj_read_id)) {
reader->read_func = read_from_io;
reader->io = io;
} else if (to_s) {
volatile VALUE rstr = rb_funcall(io, oj_to_s_id, 0);
reader->read_func = 0;
reader->in_str = StringValuePtr(rstr);
reader->head = (char*)reader->in_str;
reader->tail = reader->head;
reader->read_end = reader->head + RSTRING_LEN(rstr);
} else {
rb_raise(rb_eArgError, "parser io argument must be a String or respond to readpartial() or read().\n");
}
}
int
oj_reader_read(Reader reader) {
int err;
size_t shift = 0;
if (0 == reader->read_func) {
return -1;
}
// if there is not much room to read into, shift or realloc a larger buffer.
if (reader->head < reader->tail && 4096 > reader->end - reader->tail) {
if (0 == reader->pro) {
shift = reader->tail - reader->head;
} else {
shift = reader->pro - reader->head - 1; // leave one character so we can backup one
}
if (0 >= shift) { /* no space left so allocate more */
const char *old = reader->head;
size_t size = reader->end - reader->head + BUF_PAD;
if (reader->head == reader->base) {
reader->head = ALLOC_N(char, size * 2);
memcpy((char*)reader->head, old, size);
} else {
REALLOC_N(reader->head, char, size * 2);
}
reader->free_head = 1;
reader->end = reader->head + size * 2 - BUF_PAD;
reader->tail = reader->head + (reader->tail - old);
reader->read_end = reader->head + (reader->read_end - old);
if (0 != reader->pro) {
reader->pro = reader->head + (reader->pro - old);
}
if (0 != reader->str) {
reader->str = reader->head + (reader->str - old);
}
} else {
memmove((char*)reader->head, reader->head + shift, reader->read_end - (reader->head + shift));
reader->tail -= shift;
reader->read_end -= shift;
if (0 != reader->pro) {
reader->pro -= shift;
}
if (0 != reader->str) {
reader->str -= shift;
}
}
}
err = reader->read_func(reader);
*(char*)reader->read_end = '\0';
return err;
}
static VALUE
rescue_cb(VALUE rbuf, VALUE err) {
VALUE clas = rb_obj_class(err);
if (rb_eTypeError != clas && rb_eEOFError != clas) {
Reader reader = (Reader)rbuf;
rb_raise(clas, "at line %d, column %d\n", reader->line, reader->col);
}
return Qfalse;
}
static VALUE
partial_io_cb(VALUE rbuf) {
Reader reader = (Reader)rbuf;
VALUE args[1];
VALUE rstr;
char *str;
size_t cnt;
args[0] = ULONG2NUM(reader->end - reader->tail);
rstr = rb_funcall2(reader->io, oj_readpartial_id, 1, args);
if (Qnil == rstr) {
return Qfalse;
}
str = StringValuePtr(rstr);
cnt = RSTRING_LEN(rstr);
//printf("*** partial read %lu bytes, str: '%s'\n", cnt, str);
strcpy(reader->tail, str);
reader->read_end = reader->tail + cnt;
return Qtrue;
}
static VALUE
io_cb(VALUE rbuf) {
Reader reader = (Reader)rbuf;
VALUE args[1];
VALUE rstr;
char *str;
size_t cnt;
args[0] = ULONG2NUM(reader->end - reader->tail);
rstr = rb_funcall2(reader->io, oj_read_id, 1, args);
if (Qnil == rstr) {
return Qfalse;
}
str = StringValuePtr(rstr);
cnt = RSTRING_LEN(rstr);
//printf("*** read %lu bytes, str: '%s'\n", cnt, str);
strcpy(reader->tail, str);
reader->read_end = reader->tail + cnt;
return Qtrue;
}
static int
read_from_io_partial(Reader reader) {
return (Qfalse == rb_rescue(partial_io_cb, (VALUE)reader, rescue_cb, (VALUE)reader));
}
static int
read_from_io(Reader reader) {
return (Qfalse == rb_rescue(io_cb, (VALUE)reader, rescue_cb, (VALUE)reader));
}
static int
read_from_fd(Reader reader) {
ssize_t cnt;
size_t max = reader->end - reader->tail;
cnt = read(reader->fd, reader->tail, max);
if (cnt <= 0) {
return -1;
} else if (0 != cnt) {
reader->read_end = reader->tail + cnt;
}
return 0;
}
// This is only called when the end of the string is reached so just return -1.
/*
static int
read_from_str(Reader reader) {
return -1;
}
*/
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