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Diffstat (limited to 'docs/index.rst')
| -rw-r--r-- | docs/index.rst | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/docs/index.rst b/docs/index.rst index 31d781ea..897f5529 100644 --- a/docs/index.rst +++ b/docs/index.rst @@ -36,23 +36,26 @@ Features and limitations **Features** #) Pure C runtime -#) Small code size (2–10 kB depending on processor) -#) Small ram usage (typically 200 bytes) +#) Small code size (2–10 kB depending on processor, plus any message definitions) +#) Small ram usage (typically ~300 bytes, plus any message structs) #) Allows specifying maximum size for strings and arrays, so that they can be allocated statically. #) No malloc needed: everything can be allocated statically or on the stack. #) You can use either encoder or decoder alone to cut the code size in half. +#) Support for most protobuf features, including: all data types, nested submessages, default values, repeated and optional fields, packed arrays. +#) Callback mechanism for handling messages larger than can fit in available RAM. +#) Extensive set of tests. **Limitations** #) User must provide callbacks when decoding arrays or strings without maximum size. Malloc support could be added as a separate module. -#) Some speed has been sacrificed for code size. For example varint calculations are always done in 64 bits. +#) Some speed has been sacrificed for code size. #) Encoding is focused on writing to streams. For memory buffers only it could be made more efficient. #) The deprecated Protocol Buffers feature called "groups" is not supported. #) Fields in the generated structs are ordered by the tag number, instead of the natural ordering in .proto file. #) Unknown fields are not preserved when decoding and re-encoding a message. #) Reflection (runtime introspection) is not supported. E.g. you can't request a field by giving its name in a string. #) Numeric arrays are always encoded as packed, even if not marked as packed in .proto. This causes incompatibility with decoders that do not support packed format. -#) Cyclic references between messages are not supported. They could be supported in callback-mode if there was an option in the generator to set the mode. +#) Cyclic references between messages are supported only in callback mode. Getting started =============== @@ -104,10 +107,3 @@ Debugging and testing ===================== Extensive unittests are included under the *tests* folder. Just type *make* there to run the tests. -This also generates a file called *breakpoints* which includes all lines returning *false* in nanopb. You can use this in gdb by typing *source breakpoints*, after which gdb will break on first nanopb error. - -Wishlist -======== -#) A specialized encoder for encoding to a memory buffer. Should serialize in reverse order to avoid having to determine submessage size beforehand. -#) A cleaner rewrite of the Python-based source generator. -#) Better performance for 16- and 8-bit platforms: use smaller datatypes where possible. |