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Clean up and reduce memory allocations in string escaping

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This commit is contained in:
ridiculousfish 2014-01-08 15:06:09 -08:00
parent d20f45b949
commit 041120aab4
1 changed files with 56 additions and 76 deletions
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132
common.cpp
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@ -917,61 +917,28 @@ void write_screen(const wcstring &msg, wcstring &buff)
buff.push_back(L'\n');
}
/**
Perform string escaping of a strinng by only quoting it. Assumes
the string has already been checked for characters that can not be
escaped this way.
*/
static wchar_t *escape_simple(const wchar_t *in)
/* Escape a string, storing the result in out_str */
static void escape_string_internal(const wchar_t *orig_in, size_t in_len, wcstring *out_str, escape_flags_t flags)
{
wchar_t *out;
size_t len = wcslen(in);
out = (wchar_t *)malloc(sizeof(wchar_t)*(len+3));
if (!out)
DIE_MEM();
out[0] = L'\'';
wcscpy(&out[1], in);
out[len+1]=L'\'';
out[len+2]=0;
return out;
}
wchar_t *escape(const wchar_t *in_orig, escape_flags_t flags)
{
const wchar_t *in = in_orig;
assert(orig_in != NULL);
const wchar_t *in = orig_in;
bool escape_all = !!(flags & ESCAPE_ALL);
bool no_quoted = !!(flags & ESCAPE_NO_QUOTED);
bool no_tilde = !!(flags & ESCAPE_NO_TILDE);
wchar_t *out;
wchar_t *pos;
int need_escape=0;
int need_complex_escape=0;
if (!in)
/* Avoid dereferencing all over the place */
wcstring &out = *out_str;
if (!no_quoted && in_len == 0)
{
debug(0, L"%s called with null input", __func__);
FATAL_EXIT();
out.assign(L"''");
return;
}
if (!no_quoted && (wcslen(in) == 0))
{
out = wcsdup(L"''");
if (!out)
DIE_MEM();
return out;
}
out = (wchar_t *)malloc(sizeof(wchar_t)*(wcslen(in)*4 + 1));
pos = out;
if (!out)
DIE_MEM();
while (*in != 0)
{
@ -981,14 +948,14 @@ wchar_t *escape(const wchar_t *in_orig, escape_flags_t flags)
int val = *in - ENCODE_DIRECT_BASE;
int tmp;
*(pos++) = L'\\';
*(pos++) = L'X';
out += L'\\';
out += L'X';
tmp = val/16;
*pos++ = tmp > 9? L'a'+(tmp-10):L'0'+tmp;
out += tmp > 9? L'a'+(tmp-10):L'0'+tmp;
tmp = val%16;
*pos++ = tmp > 9? L'a'+(tmp-10):L'0'+tmp;
out += tmp > 9? L'a'+(tmp-10):L'0'+tmp;
need_escape=need_complex_escape=1;
}
@ -998,32 +965,32 @@ wchar_t *escape(const wchar_t *in_orig, escape_flags_t flags)
switch (c)
{
case L'\t':
*(pos++) = L'\\';
*(pos++) = L't';
out += L'\\';
out += L't';
need_escape=need_complex_escape=1;
break;
case L'\n':
*(pos++) = L'\\';
*(pos++) = L'n';
out += L'\\';
out += L'n';
need_escape=need_complex_escape=1;
break;
case L'\b':
*(pos++) = L'\\';
*(pos++) = L'b';
out += L'\\';
out += L'b';
need_escape=need_complex_escape=1;
break;
case L'\r':
*(pos++) = L'\\';
*(pos++) = L'r';
out += L'\\';
out += L'r';
need_escape=need_complex_escape=1;
break;
case L'\x1b':
*(pos++) = L'\\';
*(pos++) = L'e';
out += L'\\';
out += L'e';
need_escape=need_complex_escape=1;
break;
@ -1033,8 +1000,8 @@ wchar_t *escape(const wchar_t *in_orig, escape_flags_t flags)
{
need_escape=need_complex_escape=1;
if (escape_all)
*pos++ = L'\\';
*pos++ = *in;
out += L'\\';
out += *in;
break;
}
@ -1063,9 +1030,9 @@ wchar_t *escape(const wchar_t *in_orig, escape_flags_t flags)
{
need_escape=1;
if (escape_all)
*pos++ = L'\\';
out += L'\\';
}
*pos++ = *in;
out += *in;
break;
}
@ -1075,9 +1042,9 @@ wchar_t *escape(const wchar_t *in_orig, escape_flags_t flags)
{
if (*in <27 && *in > 0)
{
*(pos++) = L'\\';
*(pos++) = L'c';
*(pos++) = L'a' + *in -1;
out += L'\\';
out += L'c';
out += L'a' + *in -1;
need_escape=need_complex_escape=1;
break;
@ -1086,15 +1053,15 @@ wchar_t *escape(const wchar_t *in_orig, escape_flags_t flags)
int tmp = (*in)%16;
*pos++ = L'\\';
*pos++ = L'x';
*pos++ = ((*in>15)? L'1' : L'0');
*pos++ = tmp > 9? L'a'+(tmp-10):L'0'+tmp;
out += L'\\';
out += L'x';
out += ((*in>15)? L'1' : L'0');
out += tmp > 9? L'a'+(tmp-10):L'0'+tmp;
need_escape=need_complex_escape=1;
}
else
{
*pos++ = *in;
out += *in;
}
break;
}
@ -1103,7 +1070,6 @@ wchar_t *escape(const wchar_t *in_orig, escape_flags_t flags)
in++;
}
*pos = 0;
/*
Use quoted escaping if possible, since most people find it
@ -1111,18 +1077,32 @@ wchar_t *escape(const wchar_t *in_orig, escape_flags_t flags)
*/
if (!no_quoted && need_escape && !need_complex_escape && escape_all)
{
free(out);
out = escape_simple(in_orig);
wchar_t single_quote = L'\'';
out.clear();
out.reserve(2 + in_len);
out.push_back(single_quote);
out.append(orig_in, in_len);
out.push_back(single_quote);
}
}
wchar_t *escape(const wchar_t *in, escape_flags_t flags)
{
if (!in)
{
debug(0, L"%s called with null input", __func__);
FATAL_EXIT();
}
return out;
wcstring tmp;
escape_string_internal(in, wcslen(in), &tmp, flags);
return wcsdup(tmp.c_str());
}
wcstring escape_string(const wcstring &in, escape_flags_t flags)
{
wchar_t *tmp = escape(in.c_str(), flags);
wcstring result(tmp);
free(tmp);
wcstring result;
escape_string_internal(in.c_str(), in.size(), &result, flags);
return result;
}