THUAI6/CAPI/cpp/grpc/include/upb/msg_internal.h

/*
 * Copyright (c) 2009-2021, Google LLC
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of Google LLC nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS 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 Google LLC 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.
 */

/*
** Our memory representation for parsing tables and messages themselves.
** Functions in this file are used by generated code and possibly reflection.
**
** The definitions in this file are internal to upb.
**/

#ifndef UPB_MSG_INT_H_
#define UPB_MSG_INT_H_

#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#include "upb/extension_registry.h"
#include "upb/internal/table.h"
#include "upb/msg.h"
#include "upb/upb.h"

/* Must be last. */
#include "upb/port_def.inc"

#ifdef __cplusplus
extern "C"
{
#endif

    /** upb_*Int* conversion routines ********************************************/

    UPB_INLINE int32_t _upb_Int32_FromI(int v)
    {
        return (int32_t)v;
    }

    UPB_INLINE int64_t _upb_Int64_FromLL(long long v)
    {
        return (int64_t)v;
    }

    UPB_INLINE uint32_t _upb_UInt32_FromU(unsigned v)
    {
        return (uint32_t)v;
    }

    UPB_INLINE uint64_t _upb_UInt64_FromULL(unsigned long long v)
    {
        return (uint64_t)v;
    }

    /** upb_MiniTable *************************************************************/

    /* upb_MiniTable represents the memory layout of a given upb_MessageDef.  The
     * members are public so generated code can initialize them, but users MUST NOT
     * read or write any of its members. */

    typedef struct
    {
        uint32_t number;
        uint16_t offset;
        int16_t presence;       // If >0, hasbit_index.  If <0, ~oneof_index
        uint16_t submsg_index;  // kUpb_NoSub if descriptortype != MESSAGE/GROUP/ENUM
        uint8_t descriptortype;
        uint8_t mode; /* upb_FieldMode | upb_LabelFlags |
                         (upb_FieldRep << kUpb_FieldRep_Shift) */
    } upb_MiniTable_Field;

#define kUpb_NoSub ((uint16_t)-1)

    typedef enum
    {
        kUpb_FieldMode_Map = 0,
        kUpb_FieldMode_Array = 1,
        kUpb_FieldMode_Scalar = 2,
    } upb_FieldMode;

// Mask to isolate the upb_FieldMode from field.mode.
#define kUpb_FieldMode_Mask 3

    /* Extra flags on the mode field. */
    typedef enum
    {
        kUpb_LabelFlags_IsPacked = 4,
        kUpb_LabelFlags_IsExtension = 8,
    } upb_LabelFlags;

    // Note: we sort by this number when calculating layout order.
    typedef enum
    {
        kUpb_FieldRep_1Byte = 0,
        kUpb_FieldRep_4Byte = 1,
        kUpb_FieldRep_StringView = 2,
        kUpb_FieldRep_Pointer = 3,
        kUpb_FieldRep_8Byte = 4,

        kUpb_FieldRep_Shift = 5,  // Bit offset of the rep in upb_MiniTable_Field.mode
        kUpb_FieldRep_Max = kUpb_FieldRep_8Byte,
    } upb_FieldRep;

    UPB_INLINE upb_FieldMode upb_FieldMode_Get(const upb_MiniTable_Field* field)
    {
        return (upb_FieldMode)(field->mode & 3);
    }

    UPB_INLINE bool upb_IsRepeatedOrMap(const upb_MiniTable_Field* field)
    {
        /* This works because upb_FieldMode has no value 3. */
        return !(field->mode & kUpb_FieldMode_Scalar);
    }

    UPB_INLINE bool upb_IsSubMessage(const upb_MiniTable_Field* field)
    {
        return field->descriptortype == kUpb_FieldType_Message ||
               field->descriptortype == kUpb_FieldType_Group;
    }

    struct upb_Decoder;
    struct upb_MiniTable;

    typedef const char* _upb_FieldParser(struct upb_Decoder* d, const char* ptr, upb_Message* msg, intptr_t table, uint64_t hasbits, uint64_t data);

    typedef struct
    {
        uint64_t field_data;
        _upb_FieldParser* field_parser;
    } _upb_FastTable_Entry;

    typedef struct
    {
        const int32_t* values;  // List of values <0 or >63
        uint64_t mask;          // Bits are set for acceptable value 0 <= x < 64
        int value_count;
    } upb_MiniTable_Enum;

    typedef union
    {
        const struct upb_MiniTable* submsg;
        const upb_MiniTable_Enum* subenum;
    } upb_MiniTable_Sub;

    typedef enum
    {
        kUpb_ExtMode_NonExtendable = 0,  // Non-extendable message.
        kUpb_ExtMode_Extendable = 1,     // Normal extendable message.
        kUpb_ExtMode_IsMessageSet = 2,   // MessageSet message.
        kUpb_ExtMode_IsMessageSet_ITEM =
            3,  // MessageSet item (temporary only, see decode.c)

        // During table building we steal a bit to indicate that the message is a map
        // entry.  *Only* used during table building!
        kUpb_ExtMode_IsMapEntry = 4,
    } upb_ExtMode;

    /* MessageSet wire format is:
     *   message MessageSet {
     *     repeated group Item = 1 {
     *       required int32 type_id = 2;
     *       required bytes message = 3;
     *     }
     *   }
     */
    typedef enum
    {
        _UPB_MSGSET_ITEM = 1,
        _UPB_MSGSET_TYPEID = 2,
        _UPB_MSGSET_MESSAGE = 3,
    } upb_msgext_fieldnum;

    struct upb_MiniTable
    {
        const upb_MiniTable_Sub* subs;
        const upb_MiniTable_Field* fields;
        /* Must be aligned to sizeof(void*).  Doesn't include internal members like
         * unknown fields, extension dict, pointer to msglayout, etc. */
        uint16_t size;
        uint16_t field_count;
        uint8_t ext;  // upb_ExtMode, declared as uint8_t so sizeof(ext) == 1
        uint8_t dense_below;
        uint8_t table_mask;
        uint8_t required_count;  // Required fields have the lowest hasbits.
        /* To statically initialize the tables of variable length, we need a flexible
         * array member, and we need to compile in gnu99 mode (constant initialization
         * of flexible array members is a GNU extension, not in C99 unfortunately. */
        _upb_FastTable_Entry fasttable[];
    };

    typedef struct
    {
        upb_MiniTable_Field field;
        const upb_MiniTable* extendee;
        upb_MiniTable_Sub sub; /* NULL unless submessage or proto2 enum */
    } upb_MiniTable_Extension;

    typedef struct
    {
        const upb_MiniTable** msgs;
        const upb_MiniTable_Enum** enums;
        const upb_MiniTable_Extension** exts;
        int msg_count;
        int enum_count;
        int ext_count;
    } upb_MiniTable_File;

    // Computes a bitmask in which the |l->required_count| lowest bits are set,
    // except that we skip the lowest bit (because upb never uses hasbit 0).
    //
    // Sample output:
    //    requiredmask(1) => 0b10 (0x2)
    //    requiredmask(5) => 0b111110 (0x3e)
    UPB_INLINE uint64_t upb_MiniTable_requiredmask(const upb_MiniTable* l)
    {
        int n = l->required_count;
        assert(0 < n && n <= 63);
        return ((1ULL << n) - 1) << 1;
    }

    /** upb_ExtensionRegistry *****************************************************/

    /* Adds the given extension info for message type |l| and field number |num|
     * into the registry. Returns false if this message type and field number were
     * already in the map, or if memory allocation fails. */
    bool _upb_extreg_add(upb_ExtensionRegistry* r, const upb_MiniTable_Extension** e, size_t count);

    /* Looks up the extension (if any) defined for message type |l| and field
     * number |num|.  If an extension was found, copies the field info into |*ext|
     * and returns true. Otherwise returns false. */
    const upb_MiniTable_Extension* _upb_extreg_get(const upb_ExtensionRegistry* r, const upb_MiniTable* l, uint32_t num);

    /** upb_Message ***************************************************************/

    /* Internal members of a upb_Message that track unknown fields and/or
     * extensions. We can change this without breaking binary compatibility.  We put
     * these before the user's data.  The user's upb_Message* points after the
     * upb_Message_Internal. */

    typedef struct
    {
        /* Total size of this structure, including the data that follows.
         * Must be aligned to 8, which is alignof(upb_Message_Extension) */
        uint32_t size;

        /* Offsets relative to the beginning of this structure.
         *
         * Unknown data grows forward from the beginning to unknown_end.
         * Extension data grows backward from size to ext_begin.
         * When the two meet, we're out of data and have to realloc.
         *
         * If we imagine that the final member of this struct is:
         *   char data[size - overhead];  // overhead =
         * sizeof(upb_Message_InternalData)
         *
         * Then we have:
         *   unknown data: data[0 .. (unknown_end - overhead)]
         *   extensions data: data[(ext_begin - overhead) .. (size - overhead)] */
        uint32_t unknown_end;
        uint32_t ext_begin;
        /* Data follows, as if there were an array:
         *   char data[size - sizeof(upb_Message_InternalData)]; */
    } upb_Message_InternalData;

    typedef struct
    {
        upb_Message_InternalData* internal;
        /* Message data follows. */
    } upb_Message_Internal;

    /* Maps upb_CType -> memory size. */
    extern char _upb_CTypeo_size[12];

    UPB_INLINE size_t upb_msg_sizeof(const upb_MiniTable* l)
    {
        return l->size + sizeof(upb_Message_Internal);
    }

    UPB_INLINE upb_Message* _upb_Message_New_inl(const upb_MiniTable* l, upb_Arena* a)
    {
        size_t size = upb_msg_sizeof(l);
        void* mem = upb_Arena_Malloc(a, size + sizeof(upb_Message_Internal));
        upb_Message* msg;
        if (UPB_UNLIKELY(!mem))
            return NULL;
        msg = UPB_PTR_AT(mem, sizeof(upb_Message_Internal), upb_Message);
        memset(mem, 0, size);
        return msg;
    }

    /* Creates a new messages with the given layout on the given arena. */
    upb_Message* _upb_Message_New(const upb_MiniTable* l, upb_Arena* a);

    UPB_INLINE upb_Message_Internal* upb_Message_Getinternal(upb_Message* msg)
    {
        ptrdiff_t size = sizeof(upb_Message_Internal);
        return (upb_Message_Internal*)((char*)msg - size);
    }

    /* Clears the given message. */
    void _upb_Message_Clear(upb_Message* msg, const upb_MiniTable* l);

    /* Discards the unknown fields for this message only. */
    void _upb_Message_DiscardUnknown_shallow(upb_Message* msg);

    /* Adds unknown data (serialized protobuf data) to the given message.  The data
     * is copied into the message instance. */
    bool _upb_Message_AddUnknown(upb_Message* msg, const char* data, size_t len, upb_Arena* arena);

    /** upb_Message_Extension *****************************************************/

    /* The internal representation of an extension is self-describing: it contains
     * enough information that we can serialize it to binary format without needing
     * to look it up in a upb_ExtensionRegistry.
     *
     * This representation allocates 16 bytes to data on 64-bit platforms.  This is
     * rather wasteful for scalars (in the extreme case of bool, it wastes 15
     * bytes). We accept this because we expect messages to be the most common
     * extension type. */
    typedef struct
    {
        const upb_MiniTable_Extension* ext;
        union
        {
            upb_StringView str;
            void* ptr;
            char scalar_data[8];
        } data;
    } upb_Message_Extension;

    /* Adds the given extension data to the given message. |ext| is copied into the
     * message instance. This logically replaces any previously-added extension with
     * this number */
    upb_Message_Extension* _upb_Message_GetOrCreateExtension(
        upb_Message* msg, const upb_MiniTable_Extension* ext, upb_Arena* arena
    );

    /* Returns an array of extensions for this message. Note: the array is
     * ordered in reverse relative to the order of creation. */
    const upb_Message_Extension* _upb_Message_Getexts(const upb_Message* msg, size_t* count);

    /* Returns an extension for the given field number, or NULL if no extension
     * exists for this field number. */
    const upb_Message_Extension* _upb_Message_Getext(
        const upb_Message* msg, const upb_MiniTable_Extension* ext
    );

    void _upb_Message_Clearext(upb_Message* msg, const upb_MiniTable_Extension* ext);

    void _upb_Message_Clearext(upb_Message* msg, const upb_MiniTable_Extension* ext);

    /** Hasbit access *************************************************************/

    UPB_INLINE bool _upb_hasbit(const upb_Message* msg, size_t idx)
    {
        return (*UPB_PTR_AT(msg, idx / 8, const char) & (1 << (idx % 8))) != 0;
    }

    UPB_INLINE void _upb_sethas(const upb_Message* msg, size_t idx)
    {
        (*UPB_PTR_AT(msg, idx / 8, char)) |= (char)(1 << (idx % 8));
    }

    UPB_INLINE void _upb_clearhas(const upb_Message* msg, size_t idx)
    {
        (*UPB_PTR_AT(msg, idx / 8, char)) &= (char)(~(1 << (idx % 8)));
    }

    UPB_INLINE size_t _upb_Message_Hasidx(const upb_MiniTable_Field* f)
    {
        UPB_ASSERT(f->presence > 0);
        return f->presence;
    }

    UPB_INLINE bool _upb_hasbit_field(const upb_Message* msg, const upb_MiniTable_Field* f)
    {
        return _upb_hasbit(msg, _upb_Message_Hasidx(f));
    }

    UPB_INLINE void _upb_sethas_field(const upb_Message* msg, const upb_MiniTable_Field* f)
    {
        _upb_sethas(msg, _upb_Message_Hasidx(f));
    }

    UPB_INLINE void _upb_clearhas_field(const upb_Message* msg, const upb_MiniTable_Field* f)
    {
        _upb_clearhas(msg, _upb_Message_Hasidx(f));
    }

    /** Oneof case access *********************************************************/

    UPB_INLINE uint32_t* _upb_oneofcase(upb_Message* msg, size_t case_ofs)
    {
        return UPB_PTR_AT(msg, case_ofs, uint32_t);
    }

    UPB_INLINE uint32_t _upb_getoneofcase(const void* msg, size_t case_ofs)
    {
        return *UPB_PTR_AT(msg, case_ofs, uint32_t);
    }

    UPB_INLINE size_t _upb_oneofcase_ofs(const upb_MiniTable_Field* f)
    {
        UPB_ASSERT(f->presence < 0);
        return ~(ptrdiff_t)f->presence;
    }

    UPB_INLINE uint32_t* _upb_oneofcase_field(upb_Message* msg, const upb_MiniTable_Field* f)
    {
        return _upb_oneofcase(msg, _upb_oneofcase_ofs(f));
    }

    UPB_INLINE uint32_t _upb_getoneofcase_field(const upb_Message* msg, const upb_MiniTable_Field* f)
    {
        return _upb_getoneofcase(msg, _upb_oneofcase_ofs(f));
    }

    UPB_INLINE bool _upb_has_submsg_nohasbit(const upb_Message* msg, size_t ofs)
    {
        return *UPB_PTR_AT(msg, ofs, const upb_Message*) != NULL;
    }

    /** upb_Array *****************************************************************/

    /* Our internal representation for repeated fields.  */
    typedef struct
    {
        uintptr_t data; /* Tagged ptr: low 3 bits of ptr are lg2(elem size). */
        size_t len;     /* Measured in elements. */
        size_t size;    /* Measured in elements. */
        uint64_t junk;
    } upb_Array;

    UPB_INLINE const void* _upb_array_constptr(const upb_Array* arr)
    {
        UPB_ASSERT((arr->data & 7) <= 4);
        return (void*)(arr->data & ~(uintptr_t)7);
    }

    UPB_INLINE uintptr_t _upb_array_tagptr(void* ptr, int elem_size_lg2)
    {
        UPB_ASSERT(elem_size_lg2 <= 4);
        return (uintptr_t)ptr | elem_size_lg2;
    }

    UPB_INLINE void* _upb_array_ptr(upb_Array* arr)
    {
        return (void*)_upb_array_constptr(arr);
    }

    UPB_INLINE uintptr_t _upb_tag_arrptr(void* ptr, int elem_size_lg2)
    {
        UPB_ASSERT(elem_size_lg2 <= 4);
        UPB_ASSERT(((uintptr_t)ptr & 7) == 0);
        return (uintptr_t)ptr | (unsigned)elem_size_lg2;
    }

    UPB_INLINE upb_Array* _upb_Array_New(upb_Arena* a, size_t init_size, int elem_size_lg2)
    {
        const size_t arr_size = UPB_ALIGN_UP(sizeof(upb_Array), 8);
        const size_t bytes = sizeof(upb_Array) + (init_size << elem_size_lg2);
        upb_Array* arr = (upb_Array*)upb_Arena_Malloc(a, bytes);
        if (!arr)
            return NULL;
        arr->data = _upb_tag_arrptr(UPB_PTR_AT(arr, arr_size, void), elem_size_lg2);
        arr->len = 0;
        arr->size = init_size;
        return arr;
    }

    /* Resizes the capacity of the array to be at least min_size. */
    bool _upb_array_realloc(upb_Array* arr, size_t min_size, upb_Arena* arena);

    /* Fallback functions for when the accessors require a resize. */
    void* _upb_Array_Resize_fallback(upb_Array** arr_ptr, size_t size, int elem_size_lg2, upb_Arena* arena);
    bool _upb_Array_Append_fallback(upb_Array** arr_ptr, const void* value, int elem_size_lg2, upb_Arena* arena);

    UPB_INLINE bool _upb_array_reserve(upb_Array* arr, size_t size, upb_Arena* arena)
    {
        if (arr->size < size)
            return _upb_array_realloc(arr, size, arena);
        return true;
    }

    UPB_INLINE bool _upb_Array_Resize(upb_Array* arr, size_t size, upb_Arena* arena)
    {
        if (!_upb_array_reserve(arr, size, arena))
            return false;
        arr->len = size;
        return true;
    }

    UPB_INLINE void _upb_array_detach(const void* msg, size_t ofs)
    {
        *UPB_PTR_AT(msg, ofs, upb_Array*) = NULL;
    }

    UPB_INLINE const void* _upb_array_accessor(const void* msg, size_t ofs, size_t* size)
    {
        const upb_Array* arr = *UPB_PTR_AT(msg, ofs, const upb_Array*);
        if (arr)
        {
            if (size)
                *size = arr->len;
            return _upb_array_constptr(arr);
        }
        else
        {
            if (size)
                *size = 0;
            return NULL;
        }
    }

    UPB_INLINE void* _upb_array_mutable_accessor(void* msg, size_t ofs, size_t* size)
    {
        upb_Array* arr = *UPB_PTR_AT(msg, ofs, upb_Array*);
        if (arr)
        {
            if (size)
                *size = arr->len;
            return _upb_array_ptr(arr);
        }
        else
        {
            if (size)
                *size = 0;
            return NULL;
        }
    }

    UPB_INLINE void* _upb_Array_Resize_accessor2(void* msg, size_t ofs, size_t size, int elem_size_lg2, upb_Arena* arena)
    {
        upb_Array** arr_ptr = UPB_PTR_AT(msg, ofs, upb_Array*);
        upb_Array* arr = *arr_ptr;
        if (!arr || arr->size < size)
        {
            return _upb_Array_Resize_fallback(arr_ptr, size, elem_size_lg2, arena);
        }
        arr->len = size;
        return _upb_array_ptr(arr);
    }

    UPB_INLINE bool _upb_Array_Append_accessor2(void* msg, size_t ofs, int elem_size_lg2, const void* value, upb_Arena* arena)
    {
        upb_Array** arr_ptr = UPB_PTR_AT(msg, ofs, upb_Array*);
        size_t elem_size = 1 << elem_size_lg2;
        upb_Array* arr = *arr_ptr;
        void* ptr;
        if (!arr || arr->len == arr->size)
        {
            return _upb_Array_Append_fallback(arr_ptr, value, elem_size_lg2, arena);
        }
        ptr = _upb_array_ptr(arr);
        memcpy(UPB_PTR_AT(ptr, arr->len * elem_size, char), value, elem_size);
        arr->len++;
        return true;
    }

    /* Used by old generated code, remove once all code has been regenerated. */
    UPB_INLINE int _upb_sizelg2(upb_CType type)
    {
        switch (type)
        {
            case kUpb_CType_Bool:
                return 0;
            case kUpb_CType_Float:
            case kUpb_CType_Int32:
            case kUpb_CType_UInt32:
            case kUpb_CType_Enum:
                return 2;
            case kUpb_CType_Message:
                return UPB_SIZE(2, 3);
            case kUpb_CType_Double:
            case kUpb_CType_Int64:
            case kUpb_CType_UInt64:
                return 3;
            case kUpb_CType_String:
            case kUpb_CType_Bytes:
                return UPB_SIZE(3, 4);
        }
        UPB_UNREACHABLE();
    }
    UPB_INLINE void* _upb_Array_Resize_accessor(void* msg, size_t ofs, size_t size, upb_CType type, upb_Arena* arena)
    {
        return _upb_Array_Resize_accessor2(msg, ofs, size, _upb_sizelg2(type), arena);
    }
    UPB_INLINE bool _upb_Array_Append_accessor(void* msg, size_t ofs, size_t elem_size, upb_CType type, const void* value, upb_Arena* arena)
    {
        (void)elem_size;
        return _upb_Array_Append_accessor2(msg, ofs, _upb_sizelg2(type), value, arena);
    }

    /** upb_Map *******************************************************************/

    /* Right now we use strmaps for everything.  We'll likely want to use
     * integer-specific maps for integer-keyed maps.*/
    typedef struct
    {
        /* Size of key and val, based on the map type.  Strings are represented as '0'
         * because they must be handled specially. */
        char key_size;
        char val_size;

        upb_strtable table;
    } upb_Map;

    /* Map entries aren't actually stored, they are only used during parsing.  For
     * parsing, it helps a lot if all map entry messages have the same layout.
     * The compiler and def.c must ensure that all map entries have this layout. */
    typedef struct
    {
        upb_Message_Internal internal;
        union
        {
            upb_StringView str; /* For str/bytes. */
            upb_value val;      /* For all other types. */
        } k;
        union
        {
            upb_StringView str; /* For str/bytes. */
            upb_value val;      /* For all other types. */
        } v;
    } upb_MapEntry;

    /* Creates a new map on the given arena with this key/value type. */
    upb_Map* _upb_Map_New(upb_Arena* a, size_t key_size, size_t value_size);

    /* Converting between internal table representation and user values.
     *
     * _upb_map_tokey() and _upb_map_fromkey() are inverses.
     * _upb_map_tovalue() and _upb_map_fromvalue() are inverses.
     *
     * These functions account for the fact that strings are treated differently
     * from other types when stored in a map.
     */

    UPB_INLINE upb_StringView _upb_map_tokey(const void* key, size_t size)
    {
        if (size == UPB_MAPTYPE_STRING)
        {
            return *(upb_StringView*)key;
        }
        else
        {
            return upb_StringView_FromDataAndSize((const char*)key, size);
        }
    }

    UPB_INLINE void _upb_map_fromkey(upb_StringView key, void* out, size_t size)
    {
        if (size == UPB_MAPTYPE_STRING)
        {
            memcpy(out, &key, sizeof(key));
        }
        else
        {
            memcpy(out, key.data, size);
        }
    }

    UPB_INLINE bool _upb_map_tovalue(const void* val, size_t size, upb_value* msgval, upb_Arena* a)
    {
        if (size == UPB_MAPTYPE_STRING)
        {
            upb_StringView* strp = (upb_StringView*)upb_Arena_Malloc(a, sizeof(*strp));
            if (!strp)
                return false;
            *strp = *(upb_StringView*)val;
            *msgval = upb_value_ptr(strp);
        }
        else
        {
            memcpy(msgval, val, size);
        }
        return true;
    }

    UPB_INLINE void _upb_map_fromvalue(upb_value val, void* out, size_t size)
    {
        if (size == UPB_MAPTYPE_STRING)
        {
            const upb_StringView* strp = (const upb_StringView*)upb_value_getptr(val);
            memcpy(out, strp, sizeof(upb_StringView));
        }
        else
        {
            memcpy(out, &val, size);
        }
    }

    /* Map operations, shared by reflection and generated code. */

    UPB_INLINE size_t _upb_Map_Size(const upb_Map* map)
    {
        return map->table.t.count;
    }

    UPB_INLINE bool _upb_Map_Get(const upb_Map* map, const void* key, size_t key_size, void* val, size_t val_size)
    {
        upb_value tabval;
        upb_StringView k = _upb_map_tokey(key, key_size);
        bool ret = upb_strtable_lookup2(&map->table, k.data, k.size, &tabval);
        if (ret && val)
        {
            _upb_map_fromvalue(tabval, val, val_size);
        }
        return ret;
    }

    UPB_INLINE void* _upb_map_next(const upb_Map* map, size_t* iter)
    {
        upb_strtable_iter it;
        it.t = &map->table;
        it.index = *iter;
        upb_strtable_next(&it);
        *iter = it.index;
        if (upb_strtable_done(&it))
            return NULL;
        return (void*)str_tabent(&it);
    }

    typedef enum
    {
        // LINT.IfChange
        _kUpb_MapInsertStatus_Inserted = 0,
        _kUpb_MapInsertStatus_Replaced = 1,
        _kUpb_MapInsertStatus_OutOfMemory = 2,
        // LINT.ThenChange(//depot/google3/third_party/upb/upb/map.h)
    } _upb_MapInsertStatus;

    UPB_INLINE _upb_MapInsertStatus _upb_Map_Insert(upb_Map* map, const void* key, size_t key_size, void* val, size_t val_size, upb_Arena* a)
    {
        upb_StringView strkey = _upb_map_tokey(key, key_size);
        upb_value tabval = {0};
        if (!_upb_map_tovalue(val, val_size, &tabval, a))
        {
            return _kUpb_MapInsertStatus_OutOfMemory;
        }

        /* TODO(haberman): add overwrite operation to minimize number of lookups. */
        bool removed =
            upb_strtable_remove2(&map->table, strkey.data, strkey.size, NULL);
        if (!upb_strtable_insert(&map->table, strkey.data, strkey.size, tabval, a))
        {
            return _kUpb_MapInsertStatus_OutOfMemory;
        }
        return removed ? _kUpb_MapInsertStatus_Replaced : _kUpb_MapInsertStatus_Inserted;
    }

    UPB_INLINE bool _upb_Map_Delete(upb_Map* map, const void* key, size_t key_size)
    {
        upb_StringView k = _upb_map_tokey(key, key_size);
        return upb_strtable_remove2(&map->table, k.data, k.size, NULL);
    }

    UPB_INLINE void _upb_Map_Clear(upb_Map* map)
    {
        upb_strtable_clear(&map->table);
    }

    /* Message map operations, these get the map from the message first. */

    UPB_INLINE size_t _upb_msg_map_size(const upb_Message* msg, size_t ofs)
    {
        upb_Map* map = *UPB_PTR_AT(msg, ofs, upb_Map*);
        return map ? _upb_Map_Size(map) : 0;
    }

    UPB_INLINE bool _upb_msg_map_get(const upb_Message* msg, size_t ofs, const void* key, size_t key_size, void* val, size_t val_size)
    {
        upb_Map* map = *UPB_PTR_AT(msg, ofs, upb_Map*);
        if (!map)
            return false;
        return _upb_Map_Get(map, key, key_size, val, val_size);
    }

    UPB_INLINE void* _upb_msg_map_next(const upb_Message* msg, size_t ofs, size_t* iter)
    {
        upb_Map* map = *UPB_PTR_AT(msg, ofs, upb_Map*);
        if (!map)
            return NULL;
        return _upb_map_next(map, iter);
    }

    UPB_INLINE bool _upb_msg_map_set(upb_Message* msg, size_t ofs, const void* key, size_t key_size, void* val, size_t val_size, upb_Arena* arena)
    {
        upb_Map** map = UPB_PTR_AT(msg, ofs, upb_Map*);
        if (!*map)
        {
            *map = _upb_Map_New(arena, key_size, val_size);
        }
        return _upb_Map_Insert(*map, key, key_size, val, val_size, arena) !=
               _kUpb_MapInsertStatus_OutOfMemory;
    }

    UPB_INLINE bool _upb_msg_map_delete(upb_Message* msg, size_t ofs, const void* key, size_t key_size)
    {
        upb_Map* map = *UPB_PTR_AT(msg, ofs, upb_Map*);
        if (!map)
            return false;
        return _upb_Map_Delete(map, key, key_size);
    }

    UPB_INLINE void _upb_msg_map_clear(upb_Message* msg, size_t ofs)
    {
        upb_Map* map = *UPB_PTR_AT(msg, ofs, upb_Map*);
        if (!map)
            return;
        _upb_Map_Clear(map);
    }

    /* Accessing map key/value from a pointer, used by generated code only. */

    UPB_INLINE void _upb_msg_map_key(const void* msg, void* key, size_t size)
    {
        const upb_tabent* ent = (const upb_tabent*)msg;
        uint32_t u32len;
        upb_StringView k;
        k.data = upb_tabstr(ent->key, &u32len);
        k.size = u32len;
        _upb_map_fromkey(k, key, size);
    }

    UPB_INLINE void _upb_msg_map_value(const void* msg, void* val, size_t size)
    {
        const upb_tabent* ent = (const upb_tabent*)msg;
        upb_value v = {ent->val.val};
        _upb_map_fromvalue(v, val, size);
    }

    UPB_INLINE void _upb_msg_map_set_value(void* msg, const void* val, size_t size)
    {
        upb_tabent* ent = (upb_tabent*)msg;
        /* This is like _upb_map_tovalue() except the entry already exists so we can
         * reuse the allocated upb_StringView for string fields. */
        if (size == UPB_MAPTYPE_STRING)
        {
            upb_StringView* strp = (upb_StringView*)(uintptr_t)ent->val.val;
            memcpy(strp, val, sizeof(*strp));
        }
        else
        {
            memcpy(&ent->val.val, val, size);
        }
    }

    /** _upb_mapsorter ************************************************************/

    /* _upb_mapsorter sorts maps and provides ordered iteration over the entries.
     * Since maps can be recursive (map values can be messages which contain other
     * maps). _upb_mapsorter can contain a stack of maps. */

    typedef struct
    {
        upb_tabent const** entries;
        int size;
        int cap;
    } _upb_mapsorter;

    typedef struct
    {
        int start;
        int pos;
        int end;
    } _upb_sortedmap;

    UPB_INLINE void _upb_mapsorter_init(_upb_mapsorter* s)
    {
        s->entries = NULL;
        s->size = 0;
        s->cap = 0;
    }

    UPB_INLINE void _upb_mapsorter_destroy(_upb_mapsorter* s)
    {
        if (s->entries)
            free(s->entries);
    }

    bool _upb_mapsorter_pushmap(_upb_mapsorter* s, upb_FieldType key_type, const upb_Map* map, _upb_sortedmap* sorted);

    UPB_INLINE void _upb_mapsorter_popmap(_upb_mapsorter* s, _upb_sortedmap* sorted)
    {
        s->size = sorted->start;
    }

    UPB_INLINE bool _upb_sortedmap_next(_upb_mapsorter* s, const upb_Map* map, _upb_sortedmap* sorted, upb_MapEntry* ent)
    {
        if (sorted->pos == sorted->end)
            return false;
        const upb_tabent* tabent = s->entries[sorted->pos++];
        upb_StringView key = upb_tabstrview(tabent->key);
        _upb_map_fromkey(key, &ent->k, map->key_size);
        upb_value val = {tabent->val.val};
        _upb_map_fromvalue(val, &ent->v, map->val_size);
        return true;
    }

#ifdef __cplusplus
} /* extern "C" */
#endif

#include "upb/port_undef.inc"

#endif /* UPB_MSG_INT_H_ */