ICU-400.37.tar.gz

[apple/icu.git] / icuSources / common / utrie.h

diff --git a/icuSources/common/utrie.h b/icuSources/common/utrie.h
index 0492f0f0bffc2bded6c0b97b1634167b6b1af160..d8d77ac4cbb23e5e1e0c661d1f9ce1c5439f4cc6 100644 (file)
--- a/icuSources/common/utrie.h
+++ b/icuSources/common/utrie.h
@@ -1,7 +1,7 @@
 /*
 ******************************************************************************
 *
-*   Copyright (C) 2001-2004, International Business Machines
+*   Copyright (C) 2001-2006, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 *
 ******************************************************************************
@@ -110,6 +110,23 @@ enum {
  */
 #define UTRIE_MAX_BUILD_TIME_DATA_LENGTH (0x110000+UTRIE_DATA_BLOCK_LENGTH+0x400)
 
+/**
+ * Number of bytes for a dummy trie.
+ * A dummy trie is an empty runtime trie, used when a real data trie cannot
+ * be loaded.
+ * The number of bytes works for Latin-1-linear tries with 32-bit data
+ * (worst case).
+ *
+ * Calculation:
+ *   BMP index + 1 index block for lead surrogate code points +
+ *   Latin-1-linear array + 1 data block for lead surrogate code points
+ *
+ * Latin-1: if(UTRIE_SHIFT<=8) { 256 } else { included in first data block }
+ *
+ * @see utrie_unserializeDummy
+ */
+#define UTRIE_DUMMY_SIZE ((UTRIE_BMP_INDEX_LENGTH+UTRIE_SURROGATE_BLOCK_COUNT)*2+(UTRIE_SHIFT<=8?256:UTRIE_DATA_BLOCK_LENGTH)*4+UTRIE_DATA_BLOCK_LENGTH*4)
+
 /**
  * Runtime UTrie callback function.
  * Extract from a lead surrogate's data the
@@ -483,6 +500,45 @@ utrie_enum(const UTrie *trie,
 U_CAPI int32_t U_EXPORT2
 utrie_unserialize(UTrie *trie, const void *data, int32_t length, UErrorCode *pErrorCode);
 
+/**
+ * "Unserialize" a dummy trie.
+ * A dummy trie is an empty runtime trie, used when a real data trie cannot
+ * be loaded.
+ *
+ * The input memory is filled so that the trie always returns the initialValue,
+ * or the leadUnitValue for lead surrogate code points.
+ * The Latin-1 part is always set up to be linear.
+ *
+ * @param trie a pointer to the runtime trie structure
+ * @param data a pointer to 32-bit-aligned memory to be filled with the dummy trie data
+ * @param length the number of bytes available at data (recommended to use UTRIE_DUMMY_SIZE)
+ * @param initialValue the initial value that is set for all code points
+ * @param leadUnitValue the value for lead surrogate code _units_ that do not
+ *                      have associated supplementary data
+ * @param pErrorCode an in/out ICU UErrorCode
+ *
+ * @see UTRIE_DUMMY_SIZE
+ * @see utrie_open
+ */
+U_CAPI int32_t U_EXPORT2
+utrie_unserializeDummy(UTrie *trie,
+                       void *data, int32_t length,
+                       uint32_t initialValue, uint32_t leadUnitValue,
+                       UBool make16BitTrie,
+                       UErrorCode *pErrorCode);
+
+/**
+ * Default implementation for UTrie.getFoldingOffset, set automatically by
+ * utrie_unserialize().
+ * Simply returns the lead surrogate's value itself - which is the inverse
+ * of the default folding function used by utrie_serialize().
+ * Exported for static const UTrie structures.
+ *
+ * @see UTrieGetFoldingOffset
+ */
+U_CAPI int32_t U_EXPORT2
+utrie_defaultGetFoldingOffset(uint32_t data);
+
 /* Building a trie ----------------------------------------------------------*/
 
 /**
@@ -680,6 +736,57 @@ utrie_swap(const UDataSwapper *ds,
            const void *inData, int32_t length, void *outData,
            UErrorCode *pErrorCode);
 
+/* serialization ------------------------------------------------------------ */
+
+/**
+ * Trie data structure in serialized form:
+ *
+ * UTrieHeader header;
+ * uint16_t index[header.indexLength];
+ * uint16_t data[header.dataLength];
+ * @internal
+ */
+typedef struct UTrieHeader {
+    /** "Trie" in big-endian US-ASCII (0x54726965) */
+    uint32_t signature;
+
+    /**
+     * options bit field:
+     *     9    1=Latin-1 data is stored linearly at data+UTRIE_DATA_BLOCK_LENGTH
+     *     8    0=16-bit data, 1=32-bit data
+     *  7..4    UTRIE_INDEX_SHIFT   // 0..UTRIE_SHIFT
+     *  3..0    UTRIE_SHIFT         // 1..9
+     */
+    uint32_t options;
+
+    /** indexLength is a multiple of UTRIE_SURROGATE_BLOCK_COUNT */
+    int32_t indexLength;
+
+    /** dataLength>=UTRIE_DATA_BLOCK_LENGTH */
+    int32_t dataLength;
+} UTrieHeader;
+
+/**
+ * Constants for use with UTrieHeader.options.
+ * @internal
+ */
+enum {
+    /** Mask to get the UTRIE_SHIFT value from options. */
+    UTRIE_OPTIONS_SHIFT_MASK=0xf,
+
+    /** Shift options right this much to get the UTRIE_INDEX_SHIFT value. */
+    UTRIE_OPTIONS_INDEX_SHIFT=4,
+
+    /** If set, then the data (stage 2) array is 32 bits wide. */
+    UTRIE_OPTIONS_DATA_IS_32_BIT=0x100,
+
+    /**
+     * If set, then Latin-1 data (for U+0000..U+00ff) is stored in the data (stage 2) array
+     * as a simple, linear array at data+UTRIE_DATA_BLOCK_LENGTH.
+     */
+    UTRIE_OPTIONS_LATIN1_IS_LINEAR=0x200
+};
+
 U_CDECL_END
 
 #endif