char& string::operator [](int n)
{
acl_assert(n >= 0);
#if 1
return (*this)[(size_t) n];
#else
if (n >= CAP(vbf_))
{
int len = CAP(vbf_);
printf("%d: cap1: %d\n", __LINE__, CAP(vbf_));
space(n + 1);
printf("%d: cap2: %d\n", __LINE__, CAP(vbf_));
int new_len = CAP(vbf_);
// 初始化新分配的内存
if (new_len > len)
memset(END(vbf_), 0, new_len - len);
// 将 vbf_->vbuf.ptr 指向 n 字节处，同时修改 vbf_->vbuf.cnt 值
ACL_VSTRING_AT_OFFSET(vbf_, n);
}
else if (n >= (int) LEN(vbf_))
{
ACL_VSTRING_AT_OFFSET(vbf_, n);
ADDCH(vbf_, '\0');
TERM(vbf_);
}
return (char&) (vbf_->vbuf.data[n]);
#endif
}
char& string::operator [](size_t n)
{
// 当偏移位置大于所分配空间的最大位置，需要重新分配内存
if (n >= (size_t) CAP(vbf_))
{
int len = CAP(vbf_);
space(n + 1);
int new_len = CAP(vbf_);
// 初始化新分配的内存
if (new_len > len)
memset(END(vbf_), 0, new_len - len);
// 将 vbf_->vbuf.ptr 指向 n 字节处，同时修改 vbf_->vbuf.cnt 值
ACL_VSTRING_AT_OFFSET(vbf_, (int) n);
}
// 当偏移位置大于当前数据长度时，通过重置指针位置以修改数据长度，
// 这样当调用 length() 方法时可以获得长度
else if (n >= LEN(vbf_))
{
ACL_VSTRING_AT_OFFSET(vbf_, (int) n);
// 因为本函数返回了偏移位置 n 处的地址引用后，调用者对此引用
// 地址赋值，但并不会使缓冲区数据长度增加，所以此处在函数返回
// 前调用 ADDCH 相当于调用者外部赋值后将数据长度加 1
ADDCH(vbf_, '\0');
// 保证最后一个字节为 \0
TERM(vbf_);
}
return (char&) (vbf_->vbuf.data[n]);
}
static const char *xml_parse_meta_text(ACL_XML *xml, const char *data)
{
int ch;
if (LEN(xml->curr_node->text) == 0) {
SKIP_SPACE(data);
}
while ((ch = *data) != 0) {
if (xml->curr_node->quote) {
if (ch == xml->curr_node->quote) {
xml->curr_node->quote = 0;
}
ACL_VSTRING_ADDCH(xml->curr_node->text, ch);
} else if (IS_QUOTE(ch)) {
if (xml->curr_node->quote == 0) {
xml->curr_node->quote = ch;
}
ACL_VSTRING_ADDCH(xml->curr_node->text, ch);
} else if (ch == '<') {
xml->curr_node->nlt++;
ACL_VSTRING_ADDCH(xml->curr_node->text, ch);
} else if (ch == '>') {
if (xml->curr_node->nlt == 0) {
char *last;
size_t off;
data++;
xml->curr_node->status = ACL_XML_S_MEND;
if ((xml->curr_node->flag & ACL_XML_F_META_QM) == 0)
break;
last = acl_vstring_end(xml->curr_node->text) - 1;
if (last < STR(xml->curr_node->text) || *last != '?')
break;
off = ACL_VSTRING_LEN(xml->curr_node->text) - 1;
if (off == 0)
break;
ACL_VSTRING_AT_OFFSET(xml->curr_node->text, off);
ACL_VSTRING_TERMINATE(xml->curr_node->text);
xml_meta_attr(xml->curr_node);
break;
}
xml->curr_node->nlt--;
ACL_VSTRING_ADDCH(xml->curr_node->text, ch);
} else {
ACL_VSTRING_ADDCH(xml->curr_node->text, ch);
}
data++;
}
ACL_VSTRING_TERMINATE(xml->curr_node->text);
return (data);
}
static int vstring_extend(ACL_VBUF *bp, ssize_t incr)
{
const char *myname = "vstring_extend";
ssize_t used = (ssize_t) (bp->ptr - bp->data), new_len;
ACL_VSTRING *vp = (ACL_VSTRING *) bp;
if (vp->maxlen > 0 && (ssize_t) ACL_VSTRING_LEN(vp) >= vp->maxlen) {
ACL_VSTRING_AT_OFFSET(vp, vp->maxlen - 1);
ACL_VSTRING_TERMINATE(vp);
acl_msg_warn("%s(%d), %s: overflow maxlen: %ld, %ld",
__FILE__, __LINE__, myname, (long) vp->maxlen,
(long) ACL_VSTRING_LEN(vp));
bp->flags |= ACL_VBUF_FLAG_EOF;
return ACL_VBUF_EOF;
}
#ifdef ACL_WINDOWS
if (bp->fd == ACL_FILE_INVALID && (bp->flags & ACL_VBUF_FLAG_FIXED))
#else
if (bp->fd < 0 && (bp->flags & ACL_VBUF_FLAG_FIXED))
#endif
{
acl_msg_warn("%s(%d), %s: can't extend fixed buffer",
__FILE__, __LINE__, myname);
return ACL_VBUF_EOF;
}
/*
* Note: vp->vbuf.len is the current buffer size (both on entry and on
* exit of this routine). We round up the increment size to the buffer
* size to avoid silly little buffer increments. With really large
* strings we might want to abandon the length doubling strategy, and
* go to fixed increments.
*/
#ifdef INCR_NO_DOUBLE
/* below come from redis-server/sds.c/sdsMakeRoomFor, which can
* avoid memory double growing too large --- 2015.2.2, zsx
*/
new_len = bp->len + incr;
if (new_len < MAX_PREALLOC)
new_len *= 2;
else
new_len += MAX_PREALLOC;
#else
new_len = bp->len + (bp->len > incr ? bp->len : incr);
#endif
if (vp->maxlen > 0 && new_len > vp->maxlen)
new_len = vp->maxlen;
if (vp->slice)
bp->data = (unsigned char *) acl_slice_pool_realloc(
__FILE__, __LINE__, vp->slice, bp->data, new_len);
else if (vp->dbuf) {
const unsigned char *data = bp->data;
bp->data = (unsigned char *) acl_dbuf_pool_alloc(
vp->dbuf, new_len);
memcpy(bp->data, data, used);
acl_dbuf_pool_free(vp->dbuf, data);
} else if (bp->fd != ACL_FILE_INVALID) {
#ifdef ACL_UNIX
acl_off_t off = new_len - 1;
if (acl_lseek(bp->fd, off, SEEK_SET) != (acl_off_t) off)
acl_msg_fatal("lseek failed: %s, off: %lld",
acl_last_serror(), off);
if (acl_file_write(bp->fd, "\0", 1, 0, NULL, NULL)
== ACL_VSTREAM_EOF)
{
acl_msg_fatal("write error: %s", acl_last_serror());
}
#endif
} else
bp->data = (unsigned char *) acl_myrealloc(bp->data, new_len);
bp->len = new_len;
bp->ptr = bp->data + used;
bp->cnt = bp->len - used;
return 0;
}
