Clearing more things off my plate. Here is the -internal- utf8/ucs2

  conversion.  It's not exported, nor should it be.  Jeff suggests wrapping
  into apr_xlate, which is fine if someone would like to do so.
  This pair is for handling utf8 resource identifiers (filenames) on any
  Unicode aware platform, so that the Unicode values are invisible to the
  application (apache server).


git-svn-id: http://svn.apache.org/repos/asf/apr/apr/trunk@60594 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 369 insertions, 0 deletions

diff --git a/i18n/unix/i18n.h b/i18n/unix/i18n.h
new file mode 100644
index 000000000..da5f58f2c
--- /dev/null
+++ b/i18n/unix/i18n.h
@@ -0,0 +1,89 @@
+/* ====================================================================
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2000 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ *    if any, must include the following acknowledgment:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowledgment may appear in the software itself,
+ *    if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Apache" and "Apache Software Foundation" must
+ *    not be used to endorse or promote products derived from this
+ *    software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache",
+ *    nor may "Apache" appear in their name, without prior written
+ *    permission of the Apache Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+
+#ifndef I18N_H
+#define I18N_H
+
+#include "apr.h"
+#include "apr_xlate.h"
+
+/* If we ever support anything more exciting than char... this could move.
+ */
+typedef apr_int16_t apr_wchar_t;
+
+/**
+ * An APR internal function for fast utf-8 octet-encoded Unicode conversion
+ * to the ucs-2 wide Unicode format.  This function is used for filename and 
+ * other resource conversions for platforms providing native Unicode support.
+ *
+ * @tip Only the errors APR_EINVAL and APR_INCOMPLETE may occur, the former
+ * when the character code is invalid (in or out of context) and the later
+ * when more characters were expected, but insufficient characters remain.
+ */
+apr_status_t conv_utf8_to_ucs2(const char *in, apr_size_t *inbytes,
+                               apr_wchar_t *out, apr_size_t *outwords);
+
+/**
+ * An APR internal function for fast ucs-2 wide Unicode format conversion to 
+ * the utf-8 octet-encoded Unicode.  This function is used for filename and 
+ * other resource conversions for platforms providing native Unicode support.
+ *
+ * @tip Only the errors APR_EINVAL and APR_INCOMPLETE may occur, the former
+ * when the character code is invalid (in or out of context) and the later
+ * when more words were expected, but insufficient words remain.
+ */
+apr_status_t conv_ucs2_to_utf8(const apr_wchar_t *in, apr_size_t *inwords,
+                               char *out, apr_size_t *outbytes);
+
+#endif /* def I18N_H */
diff --git a/i18n/unix/utf8_ucs2.c b/i18n/unix/utf8_ucs2.c
new file mode 100644
index 000000000..a3dddf467
--- /dev/null
+++ b/i18n/unix/utf8_ucs2.c
@@ -0,0 +1,280 @@
+/* ====================================================================
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2000 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ *    if any, must include the following acknowledgment:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowledgment may appear in the software itself,
+ *    if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Apache" and "Apache Software Foundation" must
+ *    not be used to endorse or promote products derived from this
+ *    software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache",
+ *    nor may "Apache" appear in their name, without prior written
+ *    permission of the Apache Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+
+#include "i18n.h"
+
+/* Implement the design principal specified by RFC 2718 2.2.5 
+ * Guidelines for new URL Schemes - within the APR.
+ *
+ * Since many architectures support unicode, and UCS2 is the most
+ * efficient storage used by those archictures, these functions
+ * exist to validate a UCS string.  It is up to the operating system
+ * to determine the validitity of the string in the context of it's
+ * native language support.  File systems that support filename 
+ * characters of 0x80-0xff but have no support of Unicode will find 
+ * this function useful only for validating the character sequences 
+ * and rejecting poorly encoded strings, if RFC 2718 2.2.5 naming is
+ * desired.
+ *
+ * from RFC 2279 UTF-8, a transformation format of ISO 10646
+ *
+ *     UCS-4 range (hex.)    UTF-8 octet sequence (binary)
+ * 1:2 0000 0000-0000 007F   0xxxxxxx
+ * 2:2 0000 0080-0000 07FF   110XXXXx 10xxxxxx
+ * 3:2 0000 0800-0000 FFFF   1110XXXX 10Xxxxxx 10xxxxxx
+ * 4:4 0001 0000-001F FFFF   11110zXX 10XXxxxx 10xxxxxx 10xxxxxx
+ * inv 0020 0000-03FF FFFF   111110XX 10XXXxxx 10xxxxxx 10xxxxxx 10xxxxxx
+ * inv 0400 0000-7FFF FFFF   1111110X 10XXXXxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
+ *
+ * One of the X values must be one for the encoding length to be legit.
+ * Neither the z bit, nor the final two forms, are used for ucs-2
+ *
+ *   "Pairs of UCS-2 values between D800 and DFFF (surrogate pairs in 
+ *   Unicode parlance), being actually UCS-4 characters transformed 
+ *   through UTF-16, need special treatment: the UTF-16 transformation 
+ *   must be undone, yielding a UCS-4 character that is then transformed 
+ *   as above."
+ *
+ * from RFC2781 UTF-16: the compressed ISO 10646 encoding bitmask
+ *
+ *  U' = U - 0x10000
+ *  U' = 000000000000yyyyyyyyyyxxxxxxxxxx
+ *                  W1 = 110110yyyyyyyyyy
+ *                  W2 = 110111xxxxxxxxxx
+ *
+ * conv_utf8_to_ucs2 out bytes:  sizeof(in) * 1 <= Req <= sizeof(in) * 2
+ *
+ * conv_ucs2_to_utf8 out words:  sizeof(in) / 2 <= Req <= sizeof(in) * 3 / 2
+ */
+
+apr_status_t conv_utf8_to_ucs2(const char *in, apr_size_t *inbytes,
+                               apr_wchar_t *out, apr_size_t *outwords)
+{
+    apr_int64_t newch, mask;
+    int ch, expect, eating;
+    
+    while (*inbytes && *outwords) 
+    {
+        ch = (unsigned char)(*in++);
+        if (!(ch & 0200)) {
+            /* US-ASCII-7 plain text
+             */
+            --*inbytes;
+            --*outwords;
+            *(out++) = ch;
+        }
+        else
+        {
+            if ((ch & 0300) != 0300) { 
+                /* Multibyte Continuation is out of place
+                 */
+                return APR_EINVAL;
+            }
+            else
+            {
+                /* Multibyte Sequence Lead Character
+                 *
+                 * Compute the expected bytes while adjusting
+                 * or lead byte and leading zeros mask.
+                 */
+                mask = 0340;
+                expect = 1;
+                while ((ch & mask) == mask) {
+                    mask |= mask >> 1;
+                    if (++expect > 3) /* (truly 5 for ucs-4) */
+                        return APR_EINVAL;
+                }
+                newch = ch & ~mask;
+                eating = expect + 1;
+                if (*inbytes <= expect)
+                    return APR_INCOMPLETE;
+                /* Reject values of excessive leading 0 bits
+                 * utf-8 _demands_ the shortest possible byte length
+                 */
+                if (expect == 1) {
+                    if (!(newch & 0036))
+                        return APR_EINVAL;
+                }
+                else {
+                    /* Reject values of excessive leading 0 bits
+                     */
+                    if (!newch && !((unsigned char)*in & 0077 & (mask << 1)))
+                        return APR_EINVAL;
+                    if (expect == 2) {
+                        /* Reject values D800-DFFF when not utf16 encoded
+                         * (may not be an appropriate restriction for ucs-4)
+                         */
+                        if (newch == 0015 && ((unsigned char)*in & 0040))
+                            return APR_EINVAL;
+                    }
+                    else if (expect == 3) {
+                        /* Short circuit values > 110000
+                         */
+                        if (newch > 4)
+                            return APR_EINVAL;
+                        if (newch == 4 && ((unsigned char)*in & 0060))
+                            return APR_EINVAL;
+                    }
+                }
+                if (*outwords < (expect > 2) + 1) 
+                    break; /* buffer full */
+                while (expect--)
+                {
+                    /* Multibyte Continuation must be legal */
+                    if (((ch = (unsigned char)*(in++)) & 0300) != 0200)
+                        return APR_EINVAL;
+                    newch <<= 6;
+                    newch |= (ch & 0077);
+                }
+                *inbytes -= eating;
+                /* newch is now a true ucs-4 character
+                 *
+                 * now we need to fold to ucs-2
+                 */
+                if (newch < 0x10000) 
+                {
+                    --*outwords;
+                    *(out++) = (apr_wchar_t) newch;
+                }
+                else 
+                {
+                    *outwords -= 2;
+                    newch -= 0x10000;
+                    *(out++) = (apr_wchar_t) (0xD800 | (newch >> 10));
+                    *(out++) = (apr_wchar_t) (0xDC00 | (newch & 0x03FF));                    
+                }
+            }
+        }
+    }
+    /* Buffer full 'errors' aren't errors, the client must inspect both
+     * the inbytes and outwords values
+     */
+    return APR_SUCCESS;
+}
+
+apr_status_t conv_ucs2_to_utf8(const apr_wchar_t *in, apr_size_t *inwords,
+                               char *out, apr_size_t *outbytes)
+{
+    apr_int64_t newch, require;
+    char *invout;
+    int ch, need;
+    
+    while (*inwords && *outbytes) 
+    {
+        ch = (unsigned short)(*in++);
+        if (ch < 0x80)
+        {
+            --*inwords;
+            --*outbytes;
+            *(out++) = (unsigned char) ch;
+        }
+        else 
+        {
+            if ((ch & 0xFC00) == 0xDC00) {
+                /* Invalid Leading ucs-2 Multiword Continuation Character
+                 */
+                return APR_EINVAL;
+            }
+            if ((ch & 0xFC00) == 0xD800) {
+                /* Leading ucs-2 Multiword Character
+                 */
+                if (*inwords < 2) {
+                    /* Missing ucs-2 Multiword Continuation Character
+                     */
+                    return APR_INCOMPLETE;
+                }
+                if (((unsigned short)(*in) & 0xFC00) != 0xDC00) {
+                    /* Invalid ucs-2 Multiword Continuation Character
+                     */
+                    return APR_EINVAL;
+                }
+                newch = (ch & 0x03FF) << 10 | ((unsigned short)(*in++) & 0x03FF);
+                newch += 0x10000;
+            }
+            else {
+                /* ucs-2 Single Word Character
+                 */
+                newch = ch;
+            }
+            /* Determine the absolute minimum utf-8 bytes required
+             */
+            require = newch >> 11;
+            need = 1;
+            while (require)
+                require >>= 5, ++need;
+            if (need >= *outbytes)
+                break; /* Insufficient buffer */
+            *inwords -= (need > 2) + 1;
+            *outbytes -= need + 1;
+            /* Compute the utf-8 characters in last to first order,
+             * calculating the lead character length bits along the way.
+             */
+            ch = 0200;
+            out += need + 1;
+            invout = out;
+            while (need--) {
+                ch |= ch >> 1;
+                *(--invout) = (unsigned char)(0200 | (newch & 0077));
+                newch >>= 6;
+            }
+            /* Compute the lead utf-8 character and move the dest offset
+             */
+            *(--invout) = (unsigned char)(ch | newch);
+        }
+    }
+    /* Buffer full 'errors' aren't errors, the client must inspect both
+     * the inwords and outbytes values
+     */
+    return APR_SUCCESS;    
+}