Diff: pb_encode.c

Revision:

2:d2c61a9be078

Parent:

1:e08406101222

Child:

3:67ee10c4ae98

--- a/pb_encode.c	Fri Mar 01 12:41:26 2013 +0000
+++ b/pb_encode.c	Fri Aug 16 16:41:33 2019 +0000
@@ -3,76 +3,114 @@
  * 2011 Petteri Aimonen <jpa@kapsi.fi>
  */
 
-#define NANOPB_INTERNALS
 #include "pb.h"
 #include "pb_encode.h"
-#include <string.h>
-#include <stdio.h>
+#include "pb_common.h"
 
-/* The warn_unused_result attribute appeared first in gcc-3.4.0 */
+/* Use the GCC warn_unused_result attribute to check that all return values
+ * are propagated correctly. On other compilers and gcc before 3.4.0 just
+ * ignore the annotation.
+ */
 #if !defined(__GNUC__) || ( __GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 4)
     #define checkreturn
 #else
-    /* Verify that we remember to check all return values for proper error propagation */
     #define checkreturn __attribute__((warn_unused_result))
 #endif
 
+/**************************************
+ * Declarations internal to this file *
+ **************************************/
 typedef bool (*pb_encoder_t)(pb_ostream_t *stream, const pb_field_t *field, const void *src) checkreturn;
 
+static bool checkreturn buf_write(pb_ostream_t *stream, const pb_byte_t *buf, size_t count);
+static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *field, const void *pData, size_t count, pb_encoder_t func);
+static bool checkreturn encode_field(pb_ostream_t *stream, const pb_field_t *field, const void *pData);
+static bool checkreturn default_extension_encoder(pb_ostream_t *stream, const pb_extension_t *extension);
+static bool checkreturn encode_extension_field(pb_ostream_t *stream, const pb_field_t *field, const void *pData);
+static void *pb_const_cast(const void *p);
+static bool checkreturn pb_enc_varint(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+static bool checkreturn pb_enc_uvarint(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+static bool checkreturn pb_enc_svarint(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+static bool checkreturn pb_enc_fixed32(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+static bool checkreturn pb_enc_fixed64(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+static bool checkreturn pb_enc_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+static bool checkreturn pb_enc_string(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+static bool checkreturn pb_enc_submessage(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+static bool checkreturn pb_enc_fixed_length_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+
+#ifdef PB_WITHOUT_64BIT
+#define pb_int64_t int32_t
+#define pb_uint64_t uint32_t
+
+static bool checkreturn pb_encode_negative_varint(pb_ostream_t *stream, pb_uint64_t value);
+#else
+#define pb_int64_t int64_t
+#define pb_uint64_t uint64_t
+#endif
+
 /* --- Function pointers to field encoders ---
  * Order in the array must match pb_action_t LTYPE numbering.
  */
 static const pb_encoder_t PB_ENCODERS[PB_LTYPES_COUNT] = {
     &pb_enc_varint,
+    &pb_enc_uvarint,
     &pb_enc_svarint,
     &pb_enc_fixed32,
     &pb_enc_fixed64,
     
     &pb_enc_bytes,
     &pb_enc_string,
-    &pb_enc_submessage
+    &pb_enc_submessage,
+    NULL, /* extensions */
+    &pb_enc_fixed_length_bytes
 };
 
-/* pb_ostream_t implementation */
+/*******************************
+ * pb_ostream_t implementation *
+ *******************************/
 
-static bool checkreturn buf_write(pb_ostream_t *stream, const uint8_t *buf, size_t count)
+static bool checkreturn buf_write(pb_ostream_t *stream, const pb_byte_t *buf, size_t count)
 {
-    uint8_t *dest = (uint8_t*)stream->state;
+    size_t i;
+    pb_byte_t *dest = (pb_byte_t*)stream->state;
     stream->state = dest + count;
     
-    while (count--)
-        *dest++ = *buf++;
+    for (i = 0; i < count; i++)
+        dest[i] = buf[i];
     
     return true;
 }
 
-pb_ostream_t pb_ostream_from_buffer(uint8_t *buf, size_t bufsize)
+pb_ostream_t pb_ostream_from_buffer(pb_byte_t *buf, size_t bufsize)
 {
     pb_ostream_t stream;
 #ifdef PB_BUFFER_ONLY
-    stream.callback = (void*)1; /* Just some marker value */
+    stream.callback = (void*)1; /* Just a marker value */
 #else
     stream.callback = &buf_write;
 #endif
     stream.state = buf;
     stream.max_size = bufsize;
     stream.bytes_written = 0;
+#ifndef PB_NO_ERRMSG
+    stream.errmsg = NULL;
+#endif
     return stream;
 }
 
-bool checkreturn pb_write(pb_ostream_t *stream, const uint8_t *buf, size_t count)
+bool checkreturn pb_write(pb_ostream_t *stream, const pb_byte_t *buf, size_t count)
 {
     if (stream->callback != NULL)
     {
         if (stream->bytes_written + count > stream->max_size)
-            return false;
+            PB_RETURN_ERROR(stream, "stream full");
 
 #ifdef PB_BUFFER_ONLY
         if (!buf_write(stream, buf, count))
-            return false;
+            PB_RETURN_ERROR(stream, "io error");
 #else        
         if (!stream->callback(stream, buf, count))
-            return false;
+            PB_RETURN_ERROR(stream, "io error");
 #endif
     }
     
@@ -80,12 +118,11 @@
     return true;
 }
 
-/* Main encoding stuff */
+/*************************
+ * Encode a single field *
+ *************************/
 
-/* Callbacks don't need this function because they usually know the data type
- * without examining the field structure.
- * Therefore it is static for now.
- */
+/* Encode a static array. Handles the size calculations and possible packing. */
 static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *field,
                          const void *pData, size_t count, pb_encoder_t func)
 {
@@ -95,7 +132,11 @@
     
     if (count == 0)
         return true;
+
+    if (PB_ATYPE(field->type) != PB_ATYPE_POINTER && count > field->array_size)
+        PB_RETURN_ERROR(stream, "array max size exceeded");
     
+    /* We always pack arrays if the datatype allows it. */
     if (PB_LTYPE(field->type) <= PB_LTYPE_LAST_PACKABLE)
     {
         if (!pb_encode_tag(stream, PB_WT_STRING, field->tag))
@@ -111,8 +152,8 @@
             size = 8 * count;
         }
         else
-        {
-            pb_ostream_t sizestream = {0,0,0,0};
+        { 
+            pb_ostream_t sizestream = PB_OSTREAM_SIZING;
             p = pData;
             for (i = 0; i < count; i++)
             {
@@ -123,7 +164,7 @@
             size = sizestream.bytes_written;
         }
         
-        if (!pb_encode_varint(stream, (uint64_t)size))
+        if (!pb_encode_varint(stream, (pb_uint64_t)size))
             return false;
         
         if (stream->callback == NULL)
@@ -145,8 +186,23 @@
         {
             if (!pb_encode_tag_for_field(stream, field))
                 return false;
-            if (!func(stream, field, p))
-                return false;
+
+            /* Normally the data is stored directly in the array entries, but
+             * for pointer-type string and bytes fields, the array entries are
+             * actually pointers themselves also. So we have to dereference once
+             * more to get to the actual data. */
+            if (PB_ATYPE(field->type) == PB_ATYPE_POINTER &&
+                (PB_LTYPE(field->type) == PB_LTYPE_STRING ||
+                 PB_LTYPE(field->type) == PB_LTYPE_BYTES))
+            {
+                if (!func(stream, field, *(const void* const*)p))
+                    return false;
+            }
+            else
+            {
+                if (!func(stream, field, p))
+                    return false;
+            }
             p = (const char*)p + field->data_size;
         }
     }
@@ -154,78 +210,384 @@
     return true;
 }
 
-bool checkreturn pb_encode(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct)
+/* In proto3, all fields are optional and are only encoded if their value is "non-zero".
+ * This function implements the check for the zero value. */
+static bool pb_check_proto3_default_value(const pb_field_t *field, const void *pData)
 {
-    const pb_field_t *field = fields;
-    const void *pData = src_struct;
-    const void *pSize;
-    size_t prev_size = 0;
-    
-    while (field->tag != 0)
+    pb_type_t type = field->type;
+    const void *pSize = (const char*)pData + field->size_offset;
+
+    if (PB_HTYPE(type) == PB_HTYPE_REQUIRED)
+    {
+        /* Required proto2 fields inside proto3 submessage, pretty rare case */
+        return false;
+    }
+    else if (PB_HTYPE(type) == PB_HTYPE_REPEATED)
+    {
+        /* Repeated fields inside proto3 submessage: present if count != 0 */
+        if (field->size_offset != 0)
+            return *(const pb_size_t*)pSize == 0;
+        else
+            return false; /* Fixed length array */
+    }
+    else if (PB_HTYPE(type) == PB_HTYPE_ONEOF)
+    {
+        /* Oneof fields */
+        return *(const pb_size_t*)pSize == 0;
+    }
+    else if (PB_HTYPE(type) == PB_HTYPE_OPTIONAL && field->size_offset != 0)
+    {
+        /* Proto2 optional fields inside proto3 submessage */
+        return *(const bool*)pSize == false;
+    }
+
+    /* Rest is proto3 singular fields */
+
+    if (PB_ATYPE(type) == PB_ATYPE_STATIC)
     {
-        pb_encoder_t func = PB_ENCODERS[PB_LTYPE(field->type)];
-        pData = (const char*)pData + prev_size + field->data_offset;
+        if (PB_LTYPE(type) == PB_LTYPE_BYTES)
+        {
+            const pb_bytes_array_t *bytes = (const pb_bytes_array_t*)pData;
+            return bytes->size == 0;
+        }
+        else if (PB_LTYPE(type) == PB_LTYPE_STRING)
+        {
+            return *(const char*)pData == '\0';
+        }
+        else if (PB_LTYPE(type) == PB_LTYPE_FIXED_LENGTH_BYTES)
+        {
+            /* Fixed length bytes is only empty if its length is fixed
+             * as 0. Which would be pretty strange, but we can check
+             * it anyway. */
+            return field->data_size == 0;
+        }
+        else if (PB_LTYPE(type) == PB_LTYPE_SUBMESSAGE)
+        {
+            /* Check all fields in the submessage to find if any of them
+             * are non-zero. The comparison cannot be done byte-per-byte
+             * because the C struct may contain padding bytes that must
+             * be skipped.
+             */
+            pb_field_iter_t iter;
+            if (pb_field_iter_begin(&iter, (const pb_field_t*)field->ptr, pb_const_cast(pData)))
+            {
+                do
+                {
+                    if (!pb_check_proto3_default_value(iter.pos, iter.pData))
+                    {
+                        return false;
+                    }
+                } while (pb_field_iter_next(&iter));
+            }
+            return true;
+        }
+    }
+    
+    {
+        /* Catch-all branch that does byte-per-byte comparison for zero value.
+         *
+         * This is for all pointer fields, and for static PB_LTYPE_VARINT,
+         * UVARINT, SVARINT, FIXED32, FIXED64, EXTENSION fields, and also
+         * callback fields. These all have integer or pointer value which
+         * can be compared with 0.
+         */
+        pb_size_t i;
+        const char *p = (const char*)pData;
+        for (i = 0; i < field->data_size; i++)
+        {
+            if (p[i] != 0)
+            {
+                return false;
+            }
+        }
+
+        return true;
+    }
+}
+
+/* Encode a field with static or pointer allocation, i.e. one whose data
+ * is available to the encoder directly. */
+static bool checkreturn encode_basic_field(pb_ostream_t *stream,
+    const pb_field_t *field, const void *pData)
+{
+    pb_encoder_t func;
+    bool implicit_has;
+    const void *pSize = &implicit_has;
+    
+    func = PB_ENCODERS[PB_LTYPE(field->type)];
+    
+    if (field->size_offset)
+    {
+        /* Static optional, repeated or oneof field */
         pSize = (const char*)pData + field->size_offset;
+    }
+    else if (PB_HTYPE(field->type) == PB_HTYPE_OPTIONAL)
+    {
+        /* Proto3 style field, optional but without explicit has_ field. */
+        implicit_has = !pb_check_proto3_default_value(field, pData);
+    }
+    else
+    {
+        /* Required field, always present */
+        implicit_has = true;
+    }
+
+    if (PB_ATYPE(field->type) == PB_ATYPE_POINTER)
+    {
+        /* pData is a pointer to the field, which contains pointer to
+         * the data. If the 2nd pointer is NULL, it is interpreted as if
+         * the has_field was false.
+         */
+        pData = *(const void* const*)pData;
+        implicit_has = (pData != NULL);
+    }
+
+    switch (PB_HTYPE(field->type))
+    {
+        case PB_HTYPE_REQUIRED:
+            if (!pData)
+                PB_RETURN_ERROR(stream, "missing required field");
+            if (!pb_encode_tag_for_field(stream, field))
+                return false;
+            if (!func(stream, field, pData))
+                return false;
+            break;
         
-        prev_size = field->data_size;
-        if (PB_HTYPE(field->type) == PB_HTYPE_ARRAY)
-            prev_size *= field->array_size;
-                
-        switch (PB_HTYPE(field->type))
-        {
-            case PB_HTYPE_REQUIRED:
+        case PB_HTYPE_OPTIONAL:
+            if (*(const bool*)pSize)
+            {
                 if (!pb_encode_tag_for_field(stream, field))
                     return false;
+            
                 if (!func(stream, field, pData))
                     return false;
-                break;
-            
-            case PB_HTYPE_OPTIONAL:
-                if (*(const bool*)pSize)
-                {
-                    if (!pb_encode_tag_for_field(stream, field))
-                        return false;
-                
-                    if (!func(stream, field, pData))
-                        return false;
-                }
-                break;
-            
-            case PB_HTYPE_ARRAY:
-                if (!encode_array(stream, field, pData, *(const size_t*)pSize, func))
+            }
+            break;
+        
+        case PB_HTYPE_REPEATED: {
+            pb_size_t count;
+            if (field->size_offset != 0) {
+                count = *(const pb_size_t*)pSize;
+            } else {
+                count = field->array_size;
+            }
+            if (!encode_array(stream, field, pData, count, func))
+                return false;
+            break;
+        }
+        
+        case PB_HTYPE_ONEOF:
+            if (*(const pb_size_t*)pSize == field->tag)
+            {
+                if (!pb_encode_tag_for_field(stream, field))
                     return false;
-                break;
+
+                if (!func(stream, field, pData))
+                    return false;
+            }
+            break;
             
-            case PB_HTYPE_CALLBACK:
-            {
-                const pb_callback_t *callback = (const pb_callback_t*)pData;
-                if (callback->funcs.encode != NULL)
-                {
-                    if (!callback->funcs.encode(stream, field, callback->arg))
-                        return false;
-                }
-                break;
-            }
-        }
-    
-        field++;
+        default:
+            PB_RETURN_ERROR(stream, "invalid field type");
     }
     
     return true;
 }
 
-/* Helper functions */
-bool checkreturn pb_encode_varint(pb_ostream_t *stream, uint64_t value)
+/* Encode a field with callback semantics. This means that a user function is
+ * called to provide and encode the actual data. */
+static bool checkreturn encode_callback_field(pb_ostream_t *stream,
+    const pb_field_t *field, const void *pData)
+{
+    const pb_callback_t *callback = (const pb_callback_t*)pData;
+    
+#ifdef PB_OLD_CALLBACK_STYLE
+    const void *arg = callback->arg;
+#else
+    void * const *arg = &(callback->arg);
+#endif    
+    
+    if (callback->funcs.encode != NULL)
+    {
+        if (!callback->funcs.encode(stream, field, arg))
+            PB_RETURN_ERROR(stream, "callback error");
+    }
+    return true;
+}
+
+/* Encode a single field of any callback or static type. */
+static bool checkreturn encode_field(pb_ostream_t *stream,
+    const pb_field_t *field, const void *pData)
+{
+    switch (PB_ATYPE(field->type))
+    {
+        case PB_ATYPE_STATIC:
+        case PB_ATYPE_POINTER:
+            return encode_basic_field(stream, field, pData);
+        
+        case PB_ATYPE_CALLBACK:
+            return encode_callback_field(stream, field, pData);
+        
+        default:
+            PB_RETURN_ERROR(stream, "invalid field type");
+    }
+}
+
+/* Default handler for extension fields. Expects to have a pb_field_t
+ * pointer in the extension->type->arg field. */
+static bool checkreturn default_extension_encoder(pb_ostream_t *stream,
+    const pb_extension_t *extension)
+{
+    const pb_field_t *field = (const pb_field_t*)extension->type->arg;
+    
+    if (PB_ATYPE(field->type) == PB_ATYPE_POINTER)
+    {
+        /* For pointer extensions, the pointer is stored directly
+         * in the extension structure. This avoids having an extra
+         * indirection. */
+        return encode_field(stream, field, &extension->dest);
+    }
+    else
+    {
+        return encode_field(stream, field, extension->dest);
+    }
+}
+
+/* Walk through all the registered extensions and give them a chance
+ * to encode themselves. */
+static bool checkreturn encode_extension_field(pb_ostream_t *stream,
+    const pb_field_t *field, const void *pData)
+{
+    const pb_extension_t *extension = *(const pb_extension_t* const *)pData;
+    PB_UNUSED(field);
+    
+    while (extension)
+    {
+        bool status;
+        if (extension->type->encode)
+            status = extension->type->encode(stream, extension);
+        else
+            status = default_extension_encoder(stream, extension);
+
+        if (!status)
+            return false;
+        
+        extension = extension->next;
+    }
+    
+    return true;
+}
+
+/*********************
+ * Encode all fields *
+ *********************/
+
+static void *pb_const_cast(const void *p)
 {
-    uint8_t buffer[10];
+    /* Note: this casts away const, in order to use the common field iterator
+     * logic for both encoding and decoding. */
+    union {
+        void *p1;
+        const void *p2;
+    } t;
+    t.p2 = p;
+    return t.p1;
+}
+
+bool checkreturn pb_encode(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct)
+{
+    pb_field_iter_t iter;
+    if (!pb_field_iter_begin(&iter, fields, pb_const_cast(src_struct)))
+        return true; /* Empty message type */
+    
+    do {
+        if (PB_LTYPE(iter.pos->type) == PB_LTYPE_EXTENSION)
+        {
+            /* Special case for the extension field placeholder */
+            if (!encode_extension_field(stream, iter.pos, iter.pData))
+                return false;
+        }
+        else
+        {
+            /* Regular field */
+            if (!encode_field(stream, iter.pos, iter.pData))
+                return false;
+        }
+    } while (pb_field_iter_next(&iter));
+    
+    return true;
+}
+
+bool pb_encode_delimited(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct)
+{
+    return pb_encode_submessage(stream, fields, src_struct);
+}
+
+bool pb_encode_nullterminated(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct)
+{
+    const pb_byte_t zero = 0;
+
+    if (!pb_encode(stream, fields, src_struct))
+        return false;
+
+    return pb_write(stream, &zero, 1);
+}
+
+bool pb_get_encoded_size(size_t *size, const pb_field_t fields[], const void *src_struct)
+{
+    pb_ostream_t stream = PB_OSTREAM_SIZING;
+    
+    if (!pb_encode(&stream, fields, src_struct))
+        return false;
+    
+    *size = stream.bytes_written;
+    return true;
+}
+
+/********************
+ * Helper functions *
+ ********************/
+
+#ifdef PB_WITHOUT_64BIT
+bool checkreturn pb_encode_negative_varint(pb_ostream_t *stream, pb_uint64_t value)
+{
+  pb_byte_t buffer[10];
+  size_t i = 0;
+  size_t compensation = 32;/* we need to compensate 32 bits all set to 1 */
+
+  while (value)
+  {
+    buffer[i] = (pb_byte_t)((value & 0x7F) | 0x80);
+    value >>= 7;
+    if (compensation)
+    {
+      /* re-set all the compensation bits we can or need */
+      size_t bits = compensation > 7 ? 7 : compensation;
+      value ^= (pb_uint64_t)((0xFFu >> (8 - bits)) << 25); /* set the number of bits needed on the lowest of the most significant 7 bits */
+      compensation -= bits;
+    }
+    i++;
+  }
+  buffer[i - 1] &= 0x7F; /* Unset top bit on last byte */
+
+  return pb_write(stream, buffer, i);
+}
+#endif
+
+bool checkreturn pb_encode_varint(pb_ostream_t *stream, pb_uint64_t value)
+{
+    pb_byte_t buffer[10];
     size_t i = 0;
     
-    if (value == 0)
-        return pb_write(stream, (uint8_t*)&value, 1);
+    if (value <= 0x7F)
+    {
+        pb_byte_t v = (pb_byte_t)value;
+        return pb_write(stream, &v, 1);
+    }
     
     while (value)
     {
-        buffer[i] = (uint8_t)((value & 0x7F) | 0x80);
+        buffer[i] = (pb_byte_t)((value & 0x7F) | 0x80);
         value >>= 7;
         i++;
     }
@@ -234,54 +596,48 @@
     return pb_write(stream, buffer, i);
 }
 
-bool checkreturn pb_encode_svarint(pb_ostream_t *stream, int64_t value)
+bool checkreturn pb_encode_svarint(pb_ostream_t *stream, pb_int64_t value)
 {
-    uint64_t zigzagged;
+    pb_uint64_t zigzagged;
     if (value < 0)
-        zigzagged = (uint64_t)(~(value << 1));
+        zigzagged = ~((pb_uint64_t)value << 1);
     else
-        zigzagged = (uint64_t)(value << 1);
+        zigzagged = (pb_uint64_t)value << 1;
     
     return pb_encode_varint(stream, zigzagged);
 }
 
 bool checkreturn pb_encode_fixed32(pb_ostream_t *stream, const void *value)
 {
-    #ifdef __BIG_ENDIAN__
-    const uint8_t *bytes = value;
-    uint8_t lebytes[4];
-    lebytes[0] = bytes[3];
-    lebytes[1] = bytes[2];
-    lebytes[2] = bytes[1];
-    lebytes[3] = bytes[0];
-    return pb_write(stream, lebytes, 4);
-    #else
-    return pb_write(stream, (const uint8_t*)value, 4);
-    #endif
+    uint32_t val = *(const uint32_t*)value;
+    pb_byte_t bytes[4];
+    bytes[0] = (pb_byte_t)(val & 0xFF);
+    bytes[1] = (pb_byte_t)((val >> 8) & 0xFF);
+    bytes[2] = (pb_byte_t)((val >> 16) & 0xFF);
+    bytes[3] = (pb_byte_t)((val >> 24) & 0xFF);
+    return pb_write(stream, bytes, 4);
 }
 
+#ifndef PB_WITHOUT_64BIT
 bool checkreturn pb_encode_fixed64(pb_ostream_t *stream, const void *value)
 {
-    #ifdef __BIG_ENDIAN__
-    const uint8_t *bytes = value;
-    uint8_t lebytes[8];
-    lebytes[0] = bytes[7];
-    lebytes[1] = bytes[6];
-    lebytes[2] = bytes[5];
-    lebytes[3] = bytes[4];
-    lebytes[4] = bytes[3];
-    lebytes[5] = bytes[2];
-    lebytes[6] = bytes[1];
-    lebytes[7] = bytes[0];
-    return pb_write(stream, lebytes, 8);
-    #else
-    return pb_write(stream, (const uint8_t*)value, 8);
-    #endif
+    uint64_t val = *(const uint64_t*)value;
+    pb_byte_t bytes[8];
+    bytes[0] = (pb_byte_t)(val & 0xFF);
+    bytes[1] = (pb_byte_t)((val >> 8) & 0xFF);
+    bytes[2] = (pb_byte_t)((val >> 16) & 0xFF);
+    bytes[3] = (pb_byte_t)((val >> 24) & 0xFF);
+    bytes[4] = (pb_byte_t)((val >> 32) & 0xFF);
+    bytes[5] = (pb_byte_t)((val >> 40) & 0xFF);
+    bytes[6] = (pb_byte_t)((val >> 48) & 0xFF);
+    bytes[7] = (pb_byte_t)((val >> 56) & 0xFF);
+    return pb_write(stream, bytes, 8);
 }
+#endif
 
 bool checkreturn pb_encode_tag(pb_ostream_t *stream, pb_wire_type_t wiretype, uint32_t field_number)
 {
-    uint64_t tag = wiretype | (field_number << 3);
+    pb_uint64_t tag = ((pb_uint64_t)field_number << 3) | wiretype;
     return pb_encode_varint(stream, tag);
 }
 
@@ -291,6 +647,7 @@
     switch (PB_LTYPE(field->type))
     {
         case PB_LTYPE_VARINT:
+        case PB_LTYPE_UVARINT:
         case PB_LTYPE_SVARINT:
             wiretype = PB_WT_VARINT;
             break;
@@ -306,19 +663,20 @@
         case PB_LTYPE_BYTES:
         case PB_LTYPE_STRING:
         case PB_LTYPE_SUBMESSAGE:
+        case PB_LTYPE_FIXED_LENGTH_BYTES:
             wiretype = PB_WT_STRING;
             break;
         
         default:
-            return false;
+            PB_RETURN_ERROR(stream, "invalid field type");
     }
     
     return pb_encode_tag(stream, wiretype, field->tag);
 }
 
-bool checkreturn pb_encode_string(pb_ostream_t *stream, const uint8_t *buffer, size_t size)
+bool checkreturn pb_encode_string(pb_ostream_t *stream, const pb_byte_t *buffer, size_t size)
 {
-    if (!pb_encode_varint(stream, (uint64_t)size))
+    if (!pb_encode_varint(stream, (pb_uint64_t)size))
         return false;
     
     return pb_write(stream, buffer, size);
@@ -327,23 +685,28 @@
 bool checkreturn pb_encode_submessage(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct)
 {
     /* First calculate the message size using a non-writing substream. */
-    pb_ostream_t substream = {0,0,0,0};
+    pb_ostream_t substream = PB_OSTREAM_SIZING;
     size_t size;
     bool status;
     
     if (!pb_encode(&substream, fields, src_struct))
+    {
+#ifndef PB_NO_ERRMSG
+        stream->errmsg = substream.errmsg;
+#endif
         return false;
+    }
     
     size = substream.bytes_written;
     
-    if (!pb_encode_varint(stream, (uint64_t)size))
+    if (!pb_encode_varint(stream, (pb_uint64_t)size))
         return false;
     
     if (stream->callback == NULL)
         return pb_write(stream, NULL, size); /* Just sizing */
     
     if (stream->bytes_written + size > stream->max_size)
-        return false;
+        PB_RETURN_ERROR(stream, "stream full");
         
     /* Use a substream to verify that a callback doesn't write more than
      * what it did the first time. */
@@ -351,80 +714,158 @@
     substream.state = stream->state;
     substream.max_size = size;
     substream.bytes_written = 0;
+#ifndef PB_NO_ERRMSG
+    substream.errmsg = NULL;
+#endif
     
     status = pb_encode(&substream, fields, src_struct);
     
     stream->bytes_written += substream.bytes_written;
     stream->state = substream.state;
+#ifndef PB_NO_ERRMSG
+    stream->errmsg = substream.errmsg;
+#endif
     
     if (substream.bytes_written != size)
-        return false;
+        PB_RETURN_ERROR(stream, "submsg size changed");
     
     return status;
 }
 
 /* Field encoders */
 
-bool checkreturn pb_enc_varint(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+static bool checkreturn pb_enc_varint(pb_ostream_t *stream, const pb_field_t *field, const void *src)
 {
-    uint64_t value = 0;
+    pb_int64_t value = 0;
+    
+    if (field->data_size == sizeof(int_least8_t))
+        value = *(const int_least8_t*)src;
+    else if (field->data_size == sizeof(int_least16_t))
+        value = *(const int_least16_t*)src;
+    else if (field->data_size == sizeof(int32_t))
+        value = *(const int32_t*)src;
+    else if (field->data_size == sizeof(pb_int64_t))
+        value = *(const pb_int64_t*)src;
+    else
+        PB_RETURN_ERROR(stream, "invalid data_size");
     
-    switch (field->data_size)
-    {
-        case 1: value = *(const uint8_t*)src; break;
-        case 2: value = *(const uint16_t*)src; break;
-        case 4: value = *(const uint32_t*)src; break;
-        case 8: value = *(const uint64_t*)src; break;
-        default: return false;
-    }
+#ifdef PB_WITHOUT_64BIT
+    if (value < 0)
+      return pb_encode_negative_varint(stream, (pb_uint64_t)value);
+    else
+#endif
+      return pb_encode_varint(stream, (pb_uint64_t)value);
+}
+
+static bool checkreturn pb_enc_uvarint(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+{
+    pb_uint64_t value = 0;
+    
+    if (field->data_size == sizeof(uint_least8_t))
+        value = *(const uint_least8_t*)src;
+    else if (field->data_size == sizeof(uint_least16_t))
+        value = *(const uint_least16_t*)src;
+    else if (field->data_size == sizeof(uint32_t))
+        value = *(const uint32_t*)src;
+    else if (field->data_size == sizeof(pb_uint64_t))
+        value = *(const pb_uint64_t*)src;
+    else
+        PB_RETURN_ERROR(stream, "invalid data_size");
     
     return pb_encode_varint(stream, value);
 }
 
-bool checkreturn pb_enc_svarint(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+static bool checkreturn pb_enc_svarint(pb_ostream_t *stream, const pb_field_t *field, const void *src)
 {
-    int64_t value = 0;
+    pb_int64_t value = 0;
     
-    switch (field->data_size)
-    {
-        case 4: value = *(const int32_t*)src; break;
-        case 8: value = *(const int64_t*)src; break;
-        default: return false;
-    }
+    if (field->data_size == sizeof(int_least8_t))
+        value = *(const int_least8_t*)src;
+    else if (field->data_size == sizeof(int_least16_t))
+        value = *(const int_least16_t*)src;
+    else if (field->data_size == sizeof(int32_t))
+        value = *(const int32_t*)src;
+    else if (field->data_size == sizeof(pb_int64_t))
+        value = *(const pb_int64_t*)src;
+    else
+        PB_RETURN_ERROR(stream, "invalid data_size");
     
     return pb_encode_svarint(stream, value);
 }
 
-bool checkreturn pb_enc_fixed64(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+static bool checkreturn pb_enc_fixed64(pb_ostream_t *stream, const pb_field_t *field, const void *src)
 {
-    UNUSED(field);
+    PB_UNUSED(field);
+#ifndef PB_WITHOUT_64BIT
     return pb_encode_fixed64(stream, src);
+#else
+    PB_UNUSED(src);
+    PB_RETURN_ERROR(stream, "no 64bit support");
+#endif
 }
 
-bool checkreturn pb_enc_fixed32(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+static bool checkreturn pb_enc_fixed32(pb_ostream_t *stream, const pb_field_t *field, const void *src)
 {
-    UNUSED(field);
+    PB_UNUSED(field);
     return pb_encode_fixed32(stream, src);
 }
 
-bool checkreturn pb_enc_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+static bool checkreturn pb_enc_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src)
 {
-    const pb_bytes_array_t *bytes = (const pb_bytes_array_t*)src;
-    UNUSED(field);
+    const pb_bytes_array_t *bytes = NULL;
+
+    bytes = (const pb_bytes_array_t*)src;
+    
+    if (src == NULL)
+    {
+        /* Treat null pointer as an empty bytes field */
+        return pb_encode_string(stream, NULL, 0);
+    }
+    
+    if (PB_ATYPE(field->type) == PB_ATYPE_STATIC &&
+        PB_BYTES_ARRAY_T_ALLOCSIZE(bytes->size) > field->data_size)
+    {
+        PB_RETURN_ERROR(stream, "bytes size exceeded");
+    }
+    
     return pb_encode_string(stream, bytes->bytes, bytes->size);
 }
 
-bool checkreturn pb_enc_string(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+static bool checkreturn pb_enc_string(pb_ostream_t *stream, const pb_field_t *field, const void *src)
 {
-    UNUSED(field);
-    return pb_encode_string(stream, (const uint8_t*)src, strlen((const char*)src));
+    size_t size = 0;
+    size_t max_size = field->data_size;
+    const char *p = (const char*)src;
+    
+    if (PB_ATYPE(field->type) == PB_ATYPE_POINTER)
+        max_size = (size_t)-1;
+
+    if (src == NULL)
+    {
+        size = 0; /* Treat null pointer as an empty string */
+    }
+    else
+    {
+        /* strnlen() is not always available, so just use a loop */
+        while (size < max_size && *p != '\0')
+        {
+            size++;
+            p++;
+        }
+    }
+
+    return pb_encode_string(stream, (const pb_byte_t*)src, size);
 }
 
-bool checkreturn pb_enc_submessage(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+static bool checkreturn pb_enc_submessage(pb_ostream_t *stream, const pb_field_t *field, const void *src)
 {
     if (field->ptr == NULL)
-        return false;
+        PB_RETURN_ERROR(stream, "invalid field descriptor");
     
     return pb_encode_submessage(stream, (const pb_field_t*)field->ptr, src);
 }
 
+static bool checkreturn pb_enc_fixed_length_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+{
+    return pb_encode_string(stream, (const pb_byte_t*)src, field->data_size);
+}