initial commit, 4.5 stable

thirdparty/icu4c/common/ucmndata.cpp

@@ -0,0 +1,393 @@
+// © 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/*
+******************************************************************************
+*
+*   Copyright (C) 1999-2011, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+*
+******************************************************************************/
+
+
+/*------------------------------------------------------------------------------
+ *
+ *   UCommonData   An abstract interface for dealing with ICU Common Data Files.
+ *                 ICU Common Data Files are a grouping of a number of individual
+ *                 data items (resources, converters, tables, anything) into a
+ *                 single file or dll.  The combined format includes a table of
+ *                 contents for locating the individual items by name.
+ *
+ *                 Two formats for the table of contents are supported, which is
+ *                 why there is an abstract interface involved.
+ *
+ */
+
+#include "unicode/utypes.h"
+#include "unicode/udata.h"
+#include "cstring.h"
+#include "ucmndata.h"
+#include "udatamem.h"
+
+#if defined(UDATA_DEBUG) || defined(UDATA_DEBUG_DUMP)
+#   include <stdio.h>
+#endif
+
+U_CFUNC uint16_t
+udata_getHeaderSize(const DataHeader *udh) {
+    if(udh==nullptr) {
+        return 0;
+    } else if(udh->info.isBigEndian==U_IS_BIG_ENDIAN) {
+        /* same endianness */
+        return udh->dataHeader.headerSize;
+    } else {
+        /* opposite endianness */
+        uint16_t x=udh->dataHeader.headerSize;
+        return (uint16_t)((x<<8)|(x>>8));
+    }
+}
+
+U_CFUNC uint16_t
+udata_getInfoSize(const UDataInfo *info) {
+    if(info==nullptr) {
+        return 0;
+    } else if(info->isBigEndian==U_IS_BIG_ENDIAN) {
+        /* same endianness */
+        return info->size;
+    } else {
+        /* opposite endianness */
+        uint16_t x=info->size;
+        return (uint16_t)((x<<8)|(x>>8));
+    }
+}
+
+/*-----------------------------------------------------------------------------*
+ *                                                                             *
+ *  Pointer TOCs.   TODO: This form of table-of-contents should be removed     *
+ *                  because DLLs must be relocated on loading to correct the   *
+ *                  pointer values and this operation makes shared memory      *
+ *                  mapping of the data much less likely to work.              *
+ *                                                                             *
+ *-----------------------------------------------------------------------------*/
+typedef struct {
+    const char       *entryName;
+    const DataHeader *pHeader;
+} PointerTOCEntry;
+
+
+typedef struct  {
+    uint32_t          count;
+    uint32_t          reserved;
+    /**
+     * Variable-length array declared with length 1 to disable bounds checkers.
+     * The actual array length is in the count field.
+     */
+    PointerTOCEntry   entry[1];
+}  PointerTOC;
+
+
+/* definition of OffsetTOC struct types moved to ucmndata.h */
+
+/*-----------------------------------------------------------------------------*
+ *                                                                             *
+ *    entry point lookup implementations                                       *
+ *                                                                             *
+ *-----------------------------------------------------------------------------*/
+
+#ifndef MIN
+#define MIN(a,b) (((a)<(b)) ? (a) : (b))
+#endif
+
+/**
+ * Compare strings where we know the shared prefix length,
+ * and advance the prefix length as we find that the strings share even more characters.
+ */
+static int32_t
+strcmpAfterPrefix(const char *s1, const char *s2, int32_t *pPrefixLength) {
+    int32_t pl=*pPrefixLength;
+    int32_t cmp=0;
+    s1+=pl;
+    s2+=pl;
+    for(;;) {
+        int32_t c1 = static_cast<uint8_t>(*s1++);
+        int32_t c2 = static_cast<uint8_t>(*s2++);
+        cmp=c1-c2;
+        if(cmp!=0 || c1==0) {  /* different or done */
+            break;
+        }
+        ++pl;  /* increment shared same-prefix length */
+    }
+    *pPrefixLength=pl;
+    return cmp;
+}
+
+static int32_t
+offsetTOCPrefixBinarySearch(const char *s, const char *names,
+                            const UDataOffsetTOCEntry *toc, int32_t count) {
+    int32_t start=0;
+    int32_t limit=count;
+    /*
+     * Remember the shared prefix between s, start and limit,
+     * and don't compare that shared prefix again.
+     * The shared prefix should get longer as we narrow the [start, limit[ range.
+     */
+    int32_t startPrefixLength=0;
+    int32_t limitPrefixLength=0;
+    if(count==0) {
+        return -1;
+    }
+    /*
+     * Prime the prefix lengths so that we don't keep prefixLength at 0 until
+     * both the start and limit indexes have moved.
+     * At the same time, we find if s is one of the start and (limit-1) names,
+     * and if not, exclude them from the actual binary search.
+     */
+    if(0==strcmpAfterPrefix(s, names+toc[0].nameOffset, &startPrefixLength)) {
+        return 0;
+    }
+    ++start;
+    --limit;
+    if(0==strcmpAfterPrefix(s, names+toc[limit].nameOffset, &limitPrefixLength)) {
+        return limit;
+    }
+    while(start<limit) {
+        int32_t i=(start+limit)/2;
+        int32_t prefixLength=MIN(startPrefixLength, limitPrefixLength);
+        int32_t cmp=strcmpAfterPrefix(s, names+toc[i].nameOffset, &prefixLength);
+        if(cmp<0) {
+            limit=i;
+            limitPrefixLength=prefixLength;
+        } else if(cmp==0) {
+            return i;
+        } else {
+            start=i+1;
+            startPrefixLength=prefixLength;
+        }
+    }
+    return -1;
+}
+
+static int32_t
+pointerTOCPrefixBinarySearch(const char *s, const PointerTOCEntry *toc, int32_t count) {
+    int32_t start=0;
+    int32_t limit=count;
+    /*
+     * Remember the shared prefix between s, start and limit,
+     * and don't compare that shared prefix again.
+     * The shared prefix should get longer as we narrow the [start, limit[ range.
+     */
+    int32_t startPrefixLength=0;
+    int32_t limitPrefixLength=0;
+    if(count==0) {
+        return -1;
+    }
+    /*
+     * Prime the prefix lengths so that we don't keep prefixLength at 0 until
+     * both the start and limit indexes have moved.
+     * At the same time, we find if s is one of the start and (limit-1) names,
+     * and if not, exclude them from the actual binary search.
+     */
+    if(0==strcmpAfterPrefix(s, toc[0].entryName, &startPrefixLength)) {
+        return 0;
+    }
+    ++start;
+    --limit;
+    if(0==strcmpAfterPrefix(s, toc[limit].entryName, &limitPrefixLength)) {
+        return limit;
+    }
+    while(start<limit) {
+        int32_t i=(start+limit)/2;
+        int32_t prefixLength=MIN(startPrefixLength, limitPrefixLength);
+        int32_t cmp=strcmpAfterPrefix(s, toc[i].entryName, &prefixLength);
+        if(cmp<0) {
+            limit=i;
+            limitPrefixLength=prefixLength;
+        } else if(cmp==0) {
+            return i;
+        } else {
+            start=i+1;
+            startPrefixLength=prefixLength;
+        }
+    }
+    return -1;
+}
+
+U_CDECL_BEGIN
+static uint32_t U_CALLCONV
+offsetTOCEntryCount(const UDataMemory *pData) {
+    int32_t          retVal=0;
+    const UDataOffsetTOC *toc = (UDataOffsetTOC *)pData->toc;
+    if (toc != nullptr) {
+        retVal = toc->count;
+    }
+    return retVal;
+}
+
+static const DataHeader * U_CALLCONV
+offsetTOCLookupFn(const UDataMemory *pData,
+                  const char *tocEntryName,
+                  int32_t *pLength,
+                  UErrorCode *pErrorCode) {
+    (void)pErrorCode;
+    const UDataOffsetTOC  *toc = (UDataOffsetTOC *)pData->toc;
+    if(toc!=nullptr) {
+        const char *base=(const char *)toc;
+        int32_t number, count=(int32_t)toc->count;
+
+        /* perform a binary search for the data in the common data's table of contents */
+#if defined (UDATA_DEBUG_DUMP)
+        /* list the contents of the TOC each time .. not recommended */
+        for(number=0; number<count; ++number) {
+            fprintf(stderr, "\tx%d: %s\n", number, &base[toc->entry[number].nameOffset]);
+        }
+#endif
+        number=offsetTOCPrefixBinarySearch(tocEntryName, base, toc->entry, count);
+        if(number>=0) {
+            /* found it */
+            const UDataOffsetTOCEntry *entry=toc->entry+number;
+#ifdef UDATA_DEBUG
+            fprintf(stderr, "%s: Found.\n", tocEntryName);
+#endif
+            if((number+1) < count) {
+                *pLength = (int32_t)(entry[1].dataOffset - entry->dataOffset);
+            } else {
+                *pLength = -1;
+            }
+            return (const DataHeader *)(base+entry->dataOffset);
+        } else {
+#ifdef UDATA_DEBUG
+            fprintf(stderr, "%s: Not found.\n", tocEntryName);
+#endif
+            return nullptr;
+        }
+    } else {
+#ifdef UDATA_DEBUG
+        fprintf(stderr, "returning header\n");
+#endif
+
+        return pData->pHeader;
+    }
+}
+
+
+static uint32_t U_CALLCONV pointerTOCEntryCount(const UDataMemory *pData) {
+    const PointerTOC *toc = (PointerTOC *)pData->toc;
+    return toc != nullptr ? toc->count : 0;
+}
+
+static const DataHeader * U_CALLCONV pointerTOCLookupFn(const UDataMemory *pData,
+                   const char *name,
+                   int32_t *pLength,
+                   UErrorCode *pErrorCode) {
+    (void)pErrorCode;
+    if(pData->toc!=nullptr) {
+        const PointerTOC *toc = (PointerTOC *)pData->toc;
+        int32_t number, count=(int32_t)toc->count;
+
+#if defined (UDATA_DEBUG_DUMP)
+        /* list the contents of the TOC each time .. not recommended */
+        for(number=0; number<count; ++number) {
+            fprintf(stderr, "\tx%d: %s\n", number, toc->entry[number].entryName);
+        }
+#endif
+        number=pointerTOCPrefixBinarySearch(name, toc->entry, count);
+        if(number>=0) {
+            /* found it */
+#ifdef UDATA_DEBUG
+            fprintf(stderr, "%s: Found.\n", toc->entry[number].entryName);
+#endif
+            *pLength=-1;
+            return UDataMemory_normalizeDataPointer(toc->entry[number].pHeader);
+        } else {
+#ifdef UDATA_DEBUG
+            fprintf(stderr, "%s: Not found.\n", name);
+#endif
+            return nullptr;
+        }
+    } else {
+        return pData->pHeader;
+    }
+}
+U_CDECL_END
+
+
+static const commonDataFuncs CmnDFuncs = {offsetTOCLookupFn,  offsetTOCEntryCount};
+static const commonDataFuncs ToCPFuncs = {pointerTOCLookupFn, pointerTOCEntryCount};
+
+
+
+/*----------------------------------------------------------------------*
+ *                                                                      *
+ *  checkCommonData   Validate the format of a common data file.        *
+ *                    Fill in the virtual function ptr based on TOC type *
+ *                    If the data is invalid, close the UDataMemory     *
+ *                    and set the appropriate error code.               *
+ *                                                                      *
+ *----------------------------------------------------------------------*/
+U_CFUNC void udata_checkCommonData(UDataMemory *udm, UErrorCode *err) {
+    if (U_FAILURE(*err)) {
+        return;
+    }
+
+    if(udm==nullptr || udm->pHeader==nullptr) {
+      *err=U_INVALID_FORMAT_ERROR;
+    } else if(!(udm->pHeader->dataHeader.magic1==0xda &&
+        udm->pHeader->dataHeader.magic2==0x27 &&
+        udm->pHeader->info.isBigEndian==U_IS_BIG_ENDIAN &&
+        udm->pHeader->info.charsetFamily==U_CHARSET_FAMILY)
+        ) {
+        /* header not valid */
+        *err=U_INVALID_FORMAT_ERROR;
+    }
+    else if (udm->pHeader->info.dataFormat[0]==0x43 &&
+        udm->pHeader->info.dataFormat[1]==0x6d &&
+        udm->pHeader->info.dataFormat[2]==0x6e &&
+        udm->pHeader->info.dataFormat[3]==0x44 &&
+        udm->pHeader->info.formatVersion[0]==1
+        ) {
+        /* dataFormat="CmnD" */
+        udm->vFuncs = &CmnDFuncs;
+        udm->toc=(const char *)udm->pHeader+udata_getHeaderSize(udm->pHeader);
+    }
+    else if(udm->pHeader->info.dataFormat[0]==0x54 &&
+        udm->pHeader->info.dataFormat[1]==0x6f &&
+        udm->pHeader->info.dataFormat[2]==0x43 &&
+        udm->pHeader->info.dataFormat[3]==0x50 &&
+        udm->pHeader->info.formatVersion[0]==1
+        ) {
+        /* dataFormat="ToCP" */
+        udm->vFuncs = &ToCPFuncs;
+        udm->toc=(const char *)udm->pHeader+udata_getHeaderSize(udm->pHeader);
+    }
+    else {
+        /* dataFormat not recognized */
+        *err=U_INVALID_FORMAT_ERROR;
+    }
+
+    if (U_FAILURE(*err)) {
+        /* If the data is no good and we memory-mapped it ourselves,
+         *  close the memory mapping so it doesn't leak.  Note that this has
+         *  no effect on non-memory mapped data, other than clearing fields in udm.
+         */
+        udata_close(udm);
+    }
+}
+
+/*
+ * TODO: Add a udata_swapPackageHeader() function that swaps an ICU .dat package
+ * header but not its sub-items.
+ * This function will be needed for automatic runtime swapping.
+ * Sub-items should not be swapped to limit the swapping to the parts of the
+ * package that are actually used.
+ *
+ * Since lengths of items are implicit in the order and offsets of their
+ * ToC entries, and since offsets are relative to the start of the ToC,
+ * a swapped version may need to generate a different data structure
+ * with pointers to the original data items and with their lengths
+ * (-1 for the last one if it is not known), and maybe even pointers to the
+ * swapped versions of the items.
+ * These pointers to swapped versions would establish a cache;
+ * instead, each open data item could simply own the storage for its swapped
+ * data. This fits better with the current design.
+ *
+ * markus 2003sep18 Jitterbug 2235
+ */