Remove the PB_ENCODERS array.

Reduces code size by 2% and is overall cleaner.

pb_decode.c

@@ -32,7 +32,6 @@ typedef struct {
     void *pSize; /* Pointer where to store the size of current array field */
 } pb_field_iterator_t;
 
-typedef bool (*pb_decoder_t)(pb_istream_t *stream, const pb_field_t *field, void *dest) checkreturn;
 
 static bool checkreturn buf_read(pb_istream_t *stream, uint8_t *buf, size_t count);
 static bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest);
@@ -40,6 +39,7 @@ static bool checkreturn read_raw_value(pb_istream_t *stream, pb_wire_type_t wire
 static void pb_field_init(pb_field_iterator_t *iter, const pb_field_t *fields, void *dest_struct);
 static bool pb_field_next(pb_field_iterator_t *iter);
 static bool checkreturn pb_field_find(pb_field_iterator_t *iter, uint32_t tag);
+static bool checkreturn decode_ltype(pb_istream_t *stream, const pb_field_t *field, void *dest, pb_type_t type);
 static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iterator_t *iter);
 static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iterator_t *iter);
 static bool checkreturn decode_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iterator_t *iter);
@@ -57,21 +57,6 @@ static bool checkreturn pb_dec_submessage(pb_istream_t *stream, const pb_field_t
 static bool checkreturn pb_skip_varint(pb_istream_t *stream);
 static bool checkreturn pb_skip_string(pb_istream_t *stream);
 
-/* --- Function pointers to field decoders ---
- * Order in the array must match pb_action_t LTYPE numbering.
- */
-static const pb_decoder_t PB_DECODERS[PB_LTYPES_COUNT] = {
-    &pb_dec_varint,
-    &pb_dec_svarint,
-    &pb_dec_fixed32,
-    &pb_dec_fixed64,
-    
-    &pb_dec_bytes,
-    &pb_dec_string,
-    &pb_dec_submessage,
-    NULL /* extensions */
-};
-
 /*******************************
  * pb_istream_t implementation *
  *******************************/
@@ -313,28 +298,23 @@ static bool checkreturn read_raw_value(pb_istream_t *stream, pb_wire_type_t wire
 /* Decode string length from stream and return a substream with limited length.
  * Remember to close the substream using pb_close_string_substream().
  */
-bool checkreturn pb_make_string_substream(pb_istream_t *stream, pb_istream_t *substream)
+bool checkreturn pb_make_string_substream(pb_istream_t *stream, size_t *remaining_length)
 {
     uint32_t size;
     if (!pb_decode_varint32(stream, &size))
         return false;
-    
-    *substream = *stream;
-    if (substream->bytes_left < size)
+
+    if (stream->bytes_left < size)
         PB_RETURN_ERROR(stream, "parent stream too short");
     
-    substream->bytes_left = size;
-    stream->bytes_left -= size;
+    *remaining_length = stream->bytes_left - size;
+    stream->bytes_left = size;
     return true;
 }
 
-void pb_close_string_substream(pb_istream_t *stream, pb_istream_t *substream)
+void pb_close_string_substream(pb_istream_t *stream, size_t remaining_length)
 {
-    stream->state = substream->state;
-
-#ifndef PB_NO_ERRMSG
-    stream->errmsg = substream->errmsg;
-#endif
+    stream->bytes_left += remaining_length;
 }
 
 static void pb_field_init(pb_field_iterator_t *iter, const pb_field_t *fields, void *dest_struct)
@@ -401,22 +381,37 @@ static bool checkreturn pb_field_find(pb_field_iterator_t *iter, uint32_t tag)
  * Decode a single field *
  *************************/
 
+/* Invoke a decoder function based on the ltype of a field. */
+static bool checkreturn decode_ltype(pb_istream_t *stream,
+    const pb_field_t *field, void *dest, pb_type_t type)
+{
+    switch (PB_LTYPE(type))
+    {
+        case PB_LTYPE_VARINT:       return pb_dec_varint(stream, field, dest);
+        case PB_LTYPE_SVARINT:      return pb_dec_svarint(stream, field, dest);
+        case PB_LTYPE_FIXED32:      return pb_dec_fixed32(stream, field, dest);
+        case PB_LTYPE_FIXED64:      return pb_dec_fixed64(stream, field, dest);
+        case PB_LTYPE_BYTES:        return pb_dec_bytes(stream, field, dest);
+        case PB_LTYPE_STRING:       return pb_dec_string(stream, field, dest);
+        case PB_LTYPE_SUBMESSAGE:   return pb_dec_submessage(stream, field, dest);
+        
+        default: PB_RETURN_ERROR(stream, "invalid field type");
+    }
+}
+
 static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iterator_t *iter)
 {
     pb_type_t type;
-    pb_decoder_t func;
-    
     type = iter->pos->type;
-    func = PB_DECODERS[PB_LTYPE(type)];
 
     switch (PB_HTYPE(type))
     {
         case PB_HTYPE_REQUIRED:
-            return func(stream, iter->pos, iter->pData);
+            return decode_ltype(stream, iter->pos, iter->pData, type);
             
         case PB_HTYPE_OPTIONAL:
             *(bool*)iter->pSize = true;
-            return func(stream, iter->pos, iter->pData);
+            return decode_ltype(stream, iter->pos, iter->pData, type);
     
         case PB_HTYPE_REPEATED:
             if (wire_type == PB_WT_STRING
@@ -425,24 +420,25 @@ static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t
                 /* Packed array */
                 bool status = true;
                 size_t *size = (size_t*)iter->pSize;
-                pb_istream_t substream;
-                if (!pb_make_string_substream(stream, &substream))
+                size_t remaining_length;
+                if (!pb_make_string_substream(stream, &remaining_length))
                     return false;
                 
-                while (substream.bytes_left && *size < iter->pos->array_size)
+                while (stream->bytes_left)
                 {
                     void *pItem = (uint8_t*)iter->pData + iter->pos->data_size * (*size);
-                    if (!func(&substream, iter->pos, pItem))
+                    
+                    if (*size >= iter->pos->array_size)
+                        PB_RETURN_ERROR(stream, "array overflow");
+                
+                    if (!decode_ltype(stream, iter->pos, pItem, type))
                     {
                         status = false;
                         break;
                     }
                     (*size)++;
                 }
-                pb_close_string_substream(stream, &substream);
-                
-                if (substream.bytes_left != 0)
-                    PB_RETURN_ERROR(stream, "array overflow");
+                pb_close_string_substream(stream, remaining_length);
                 
                 return status;
             }
@@ -455,7 +451,7 @@ static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t
                     PB_RETURN_ERROR(stream, "array overflow");
                 
                 (*size)++;
-                return func(stream, iter->pos, pItem);
+                return decode_ltype(stream, iter->pos, pItem, type);
             }
 
         default:
@@ -478,18 +474,18 @@ static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type
     
     if (wire_type == PB_WT_STRING)
     {
-        pb_istream_t substream;
+        size_t remaining_length;
         
-        if (!pb_make_string_substream(stream, &substream))
+        if (!pb_make_string_substream(stream, &remaining_length))
             return false;
         
         do
         {
-            if (!pCallback->funcs.decode(&substream, iter->pos, arg))
+            if (!pCallback->funcs.decode(stream, iter->pos, arg))
                 PB_RETURN_ERROR(stream, "callback failed");
-        } while (substream.bytes_left);
+        } while (stream->bytes_left);
         
-        pb_close_string_substream(stream, &substream);
+        pb_close_string_substream(stream, remaining_length);
         return true;
     }
     else
@@ -746,14 +742,14 @@ bool checkreturn pb_decode(pb_istream_t *stream, const pb_field_t fields[], void
 
 bool pb_decode_delimited(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct)
 {
-    pb_istream_t substream;
+    size_t remaining_length;
     bool status;
     
-    if (!pb_make_string_substream(stream, &substream))
+    if (!pb_make_string_substream(stream, &remaining_length))
         return false;
     
-    status = pb_decode(&substream, fields, dest_struct);
-    pb_close_string_substream(stream, &substream);
+    status = pb_decode(stream, fields, dest_struct);
+    pb_close_string_substream(stream, remaining_length);
     return status;
 }
 
@@ -896,10 +892,10 @@ bool checkreturn pb_dec_string(pb_istream_t *stream, const pb_field_t *field, vo
 bool checkreturn pb_dec_submessage(pb_istream_t *stream, const pb_field_t *field, void *dest)
 {
     bool status;
-    pb_istream_t substream;
+    size_t remaining_length;
     const pb_field_t* submsg_fields = (const pb_field_t*)field->ptr;
     
-    if (!pb_make_string_substream(stream, &substream))
+    if (!pb_make_string_substream(stream, &remaining_length))
         return false;
     
     if (field->ptr == NULL)
@@ -908,10 +904,10 @@ bool checkreturn pb_dec_submessage(pb_istream_t *stream, const pb_field_t *field
     /* New array entries need to be initialized, while required and optional
      * submessages have already been initialized in the top-level pb_decode. */
     if (PB_HTYPE(field->type) == PB_HTYPE_REPEATED)
-        status = pb_decode(&substream, submsg_fields, dest);
+        status = pb_decode(stream, submsg_fields, dest);
     else
-        status = pb_decode_noinit(&substream, submsg_fields, dest);
+        status = pb_decode_noinit(stream, submsg_fields, dest);
     
-    pb_close_string_substream(stream, &substream);
+    pb_close_string_substream(stream, remaining_length);
     return status;
 }

pb_decode.h

@@ -128,8 +128,8 @@ bool pb_decode_fixed32(pb_istream_t *stream, void *dest);
 bool pb_decode_fixed64(pb_istream_t *stream, void *dest);
 
 /* Make a limited-length substream for reading a PB_WT_STRING field. */
-bool pb_make_string_substream(pb_istream_t *stream, pb_istream_t *substream);
-void pb_close_string_substream(pb_istream_t *stream, pb_istream_t *substream);
+bool pb_make_string_substream(pb_istream_t *stream, size_t *remaining_length);
+void pb_close_string_substream(pb_istream_t *stream, size_t remaining_length);
 
 #ifdef __cplusplus
 } /* extern "C" */

pb_encode.c

@@ -20,10 +20,9 @@
 /**************************************
  * 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 uint8_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_ltype(pb_ostream_t *stream, const pb_field_t *field, const void *src, pb_type_t type);
+static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *field, const void *pData, size_t count);
 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);
@@ -35,21 +34,6 @@ static bool checkreturn pb_enc_bytes(pb_ostream_t *stream, const pb_field_t *fie
 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);
 
-/* --- 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_svarint,
-    &pb_enc_fixed32,
-    &pb_enc_fixed64,
-    
-    &pb_enc_bytes,
-    &pb_enc_string,
-    &pb_enc_submessage,
-    NULL /* extensions */
-};
-
 /*******************************
  * pb_ostream_t implementation *
  *******************************/
@@ -106,9 +90,28 @@ bool checkreturn pb_write(pb_ostream_t *stream, const uint8_t *buf, size_t count
  * Encode a single field *
  *************************/
 
+/* Invoke an encoder function based on the ltype of a field. */
+static bool checkreturn encode_ltype(pb_ostream_t *stream,
+    const pb_field_t *field, const void *src, pb_type_t type)
+{
+    switch (PB_LTYPE(type))
+    {
+        case PB_LTYPE_VARINT:       return pb_enc_varint(stream, field, src);
+        case PB_LTYPE_SVARINT:      return pb_enc_svarint(stream, field, src);
+        case PB_LTYPE_FIXED32:      return pb_enc_fixed32(stream, field, src);
+        case PB_LTYPE_FIXED64:      return pb_enc_fixed64(stream, field, src);
+        case PB_LTYPE_BYTES:        return pb_enc_bytes(stream, field, src);
+        case PB_LTYPE_STRING:       return pb_enc_string(stream, field, src);
+        case PB_LTYPE_SUBMESSAGE:   return pb_enc_submessage(stream, field, src);
+        
+        default: PB_RETURN_ERROR(stream, "invalid field type");
+    }
+}
+    
+
 /* 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)
+                         const void *pData, size_t count)
 {
     size_t i;
     const void *p;
@@ -141,7 +144,7 @@ static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *fie
             p = pData;
             for (i = 0; i < count; i++)
             {
-                if (!func(&sizestream, field, p))
+                if (!encode_ltype(&sizestream, field, p, field->type))
                     return false;
                 p = (const char*)p + field->data_size;
             }
@@ -158,7 +161,7 @@ static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *fie
         p = pData;
         for (i = 0; i < count; i++)
         {
-            if (!func(stream, field, p))
+            if (!encode_ltype(stream, field, p, field->type))
                 return false;
             p = (const char*)p + field->data_size;
         }
@@ -170,7 +173,7 @@ static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *fie
         {
             if (!pb_encode_tag_for_field(stream, field))
                 return false;
-            if (!func(stream, field, p))
+            if (!encode_ltype(stream, field, p, field->type))
                 return false;
             p = (const char*)p + field->data_size;
         }
@@ -184,12 +187,9 @@ static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *fie
 static bool checkreturn encode_static_field(pb_ostream_t *stream,
     const pb_field_t *field, const void *pData)
 {
-    pb_encoder_t func;
     const void *pSize;
     bool dummy = true;
     
-    func = PB_ENCODERS[PB_LTYPE(field->type)];
-    
     if (field->size_offset)
         pSize = (const char*)pData + field->size_offset;
     else
@@ -200,7 +200,7 @@ static bool checkreturn encode_static_field(pb_ostream_t *stream,
         case PB_HTYPE_REQUIRED:
             if (!pb_encode_tag_for_field(stream, field))
                 return false;
-            if (!func(stream, field, pData))
+            if (!encode_ltype(stream, field, pData, field->type))
                 return false;
             break;
         
@@ -210,13 +210,13 @@ static bool checkreturn encode_static_field(pb_ostream_t *stream,
                 if (!pb_encode_tag_for_field(stream, field))
                     return false;
             
-                if (!func(stream, field, pData))
+                if (!encode_ltype(stream, field, pData, field->type))
                     return false;
             }
             break;
         
         case PB_HTYPE_REPEATED:
-            if (!encode_array(stream, field, pData, *(const size_t*)pSize, func))
+            if (!encode_array(stream, field, pData, *(const size_t*)pSize))
                 return false;
             break;