1 files changed, 81 insertions, 0 deletions
diff --git a/library/cpp/html/pcdata/pcdata.cpp b/library/cpp/html/pcdata/pcdata.cpp
new file mode 100644
index 00000000000..740c240fd23
--- /dev/null
+++ b/library/cpp/html/pcdata/pcdata.cpp
@@ -0,0 +1,81 @@
+#include "pcdata.h"
+
+#include <util/string/strspn.h>
+
+static TCompactStrSpn sspn("\"<>&'");
+
+static void EncodeHtmlPcdataAppendInternal(const TStringBuf str, TString& strout, bool qAmp) {
+    const char* s = str.data();
+    const char* e = s + str.length();
+
+    for (;;) {
+        const char* next = sspn.FindFirstOf(s, e);
+
+        strout.AppendNoAlias(s, next - s);
+        s = next;
+
+        if (s == e)
+            break;
+
+        switch (*s) {
+            case '\"':
+                strout += TStringBuf("&quot;");
+                ++s;
+                break;
+
+            case '<':
+                strout += TStringBuf("&lt;");
+                ++s;
+                break;
+
+            case '>':
+                strout += TStringBuf("&gt;");
+                ++s;
+                break;
+
+            case '\'':
+                strout += TStringBuf("&#39;");
+                ++s;
+                break;
+
+            case '&':
+                if (qAmp)
+                    strout += TStringBuf("&amp;");
+                else
+                    strout += TStringBuf("&");
+                ++s;
+                break;
+        }
+    }
+}
+
+void EncodeHtmlPcdataAppend(const TStringBuf str, TString& strout) {
+    EncodeHtmlPcdataAppendInternal(str, strout, true);
+}
+
+TString EncodeHtmlPcdata(const TStringBuf str, bool qAmp) {
+    TString strout;
+    EncodeHtmlPcdataAppendInternal(str, strout, qAmp);
+    return strout;
+}
+
+TString DecodeHtmlPcdata(const TString& sz) {
+    TString res;
+    const char* codes[] = {"&quot;", "&lt;", "&gt;", "&#39;", "&#039;", "&amp;", "&apos;", nullptr};
+    const char chars[] = {'\"', '<', '>', '\'', '\'', '&', '\''};
+    for (size_t i = 0; i < sz.length(); ++i) {
+        char c = sz[i];
+        if (c == '&') {
+            for (const char** p = codes; *p; ++p) {
+                size_t len = strlen(*p);
+                if (strncmp(sz.c_str() + i, *p, len) == 0) {
+                    i += len - 1;
+                    c = chars[p - codes];
+                    break;
+                }
+            }
+        }
+        res += c;
+    }
+    return res;
+}