diff options
Diffstat (limited to 'libs/nanopb/examples')
29 files changed, 1316 insertions, 0 deletions
diff --git a/libs/nanopb/examples/cmake_simple/CMakeLists.txt b/libs/nanopb/examples/cmake_simple/CMakeLists.txt new file mode 100644 index 0000000..e5f33a0 --- /dev/null +++ b/libs/nanopb/examples/cmake_simple/CMakeLists.txt @@ -0,0 +1,16 @@ +cmake_minimum_required(VERSION 2.8) +project(NANOPB_CMAKE_SIMPLE C) + +set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/../../extra) +find_package(Nanopb REQUIRED) +include_directories(${NANOPB_INCLUDE_DIRS}) + +nanopb_generate_cpp(PROTO_SRCS PROTO_HDRS simple.proto) +include_directories(${CMAKE_CURRENT_BINARY_DIR}) +#add_custom_target(generate_proto_sources DEPENDS ${PROTO_SRCS} ${PROTO_HDRS}) +set_source_files_properties(${PROTO_SRCS} ${PROTO_HDRS} + PROPERTIES GENERATED TRUE) + +set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Werror -g -O0") + +add_executable(simple simple.c ${PROTO_SRCS} ${PROTO_HDRS}) diff --git a/libs/nanopb/examples/cmake_simple/README.txt b/libs/nanopb/examples/cmake_simple/README.txt new file mode 100644 index 0000000..aa0f3f3 --- /dev/null +++ b/libs/nanopb/examples/cmake_simple/README.txt @@ -0,0 +1,18 @@ +Nanopb example "simple" using CMake +======================= + +This example is the same as the simple nanopb example but built using CMake. + +Example usage +------------- + +On Linux, create a build directory and then call cmake: + + nanopb/examples/cmake_simple$ mkdir build + nanopb/examples/cmake_simple$ cd build/ + nanopb/examples/cmake_simple/build$ cmake .. + nanopb/examples/cmake_simple/build$ make + +After that, you can run it with the command: ./simple + +On other platforms supported by CMake, refer to CMake instructions. diff --git a/libs/nanopb/examples/cmake_simple/simple.c b/libs/nanopb/examples/cmake_simple/simple.c new file mode 100644 index 0000000..1f6b137 --- /dev/null +++ b/libs/nanopb/examples/cmake_simple/simple.c @@ -0,0 +1,71 @@ +#include <stdio.h> +#include <pb_encode.h> +#include <pb_decode.h> +#include "simple.pb.h" + +int main() +{ + /* This is the buffer where we will store our message. */ + uint8_t buffer[128]; + size_t message_length; + bool status; + + /* Encode our message */ + { + /* Allocate space on the stack to store the message data. + * + * Nanopb generates simple struct definitions for all the messages. + * - check out the contents of simple.pb.h! + * It is a good idea to always initialize your structures + * so that you do not have garbage data from RAM in there. + */ + SimpleMessage message = SimpleMessage_init_zero; + + /* Create a stream that will write to our buffer. */ + pb_ostream_t stream = pb_ostream_from_buffer(buffer, sizeof(buffer)); + + /* Fill in the lucky number */ + message.lucky_number = 13; + + /* Now we are ready to encode the message! */ + status = pb_encode(&stream, SimpleMessage_fields, &message); + message_length = stream.bytes_written; + + /* Then just check for any errors.. */ + if (!status) + { + printf("Encoding failed: %s\n", PB_GET_ERROR(&stream)); + return 1; + } + } + + /* Now we could transmit the message over network, store it in a file or + * wrap it to a pigeon's leg. + */ + + /* But because we are lazy, we will just decode it immediately. */ + + { + /* Allocate space for the decoded message. */ + SimpleMessage message = SimpleMessage_init_zero; + + /* Create a stream that reads from the buffer. */ + pb_istream_t stream = pb_istream_from_buffer(buffer, message_length); + + /* Now we are ready to decode the message. */ + status = pb_decode(&stream, SimpleMessage_fields, &message); + + /* Check for errors... */ + if (!status) + { + printf("Decoding failed: %s\n", PB_GET_ERROR(&stream)); + return 1; + } + + /* Print the data contained in the message. */ + printf("Your lucky number was %d!\n", message.lucky_number); + } + + return 0; +} + diff --git a/libs/nanopb/examples/cmake_simple/simple.proto b/libs/nanopb/examples/cmake_simple/simple.proto new file mode 100644 index 0000000..5c73a3b --- /dev/null +++ b/libs/nanopb/examples/cmake_simple/simple.proto @@ -0,0 +1,9 @@ +// A very simple protocol definition, consisting of only +// one message. + +syntax = "proto2"; + +message SimpleMessage { + required int32 lucky_number = 1; +} + diff --git a/libs/nanopb/examples/network_server/Makefile b/libs/nanopb/examples/network_server/Makefile new file mode 100644 index 0000000..2c7639a --- /dev/null +++ b/libs/nanopb/examples/network_server/Makefile @@ -0,0 +1,17 @@ +# Include the nanopb provided Makefile rules +include ../../extra/nanopb.mk + +# Compiler flags to enable all warnings & debug info +CFLAGS = -ansi -Wall -Werror -g -O0 +CFLAGS += -I$(NANOPB_DIR) + +all: server client + +.SUFFIXES: + +clean: + rm -f server client fileproto.pb.c fileproto.pb.h + +%: %.c common.c fileproto.pb.c + $(CC) $(CFLAGS) -o $@ $^ $(NANOPB_CORE) + diff --git a/libs/nanopb/examples/network_server/README.txt b/libs/nanopb/examples/network_server/README.txt new file mode 100644 index 0000000..7bdcbed --- /dev/null +++ b/libs/nanopb/examples/network_server/README.txt @@ -0,0 +1,60 @@ +Nanopb example "network_server" +=============================== + +This example demonstrates the use of nanopb to communicate over network +connections. It consists of a server that sends file listings, and of +a client that requests the file list from the server. + +Example usage +------------- + +user@host:~/nanopb/examples/network_server$ make # Build the example +protoc -ofileproto.pb fileproto.proto +python ../../generator/nanopb_generator.py fileproto.pb +Writing to fileproto.pb.h and fileproto.pb.c +cc -ansi -Wall -Werror -I .. -g -O0 -I../.. -o server server.c + ../../pb_decode.c ../../pb_encode.c fileproto.pb.c common.c +cc -ansi -Wall -Werror -I .. -g -O0 -I../.. -o client client.c + ../../pb_decode.c ../../pb_encode.c fileproto.pb.c common.c + +user@host:~/nanopb/examples/network_server$ ./server & # Start the server on background +[1] 24462 + +petteri@oddish:~/nanopb/examples/network_server$ ./client /bin # Request the server to list /bin +Got connection. +Listing directory: /bin +1327119 bzdiff +1327126 bzless +1327147 ps +1327178 ntfsmove +1327271 mv +1327187 mount +1327259 false +1327266 tempfile +1327285 zfgrep +1327165 gzexe +1327204 nc.openbsd +1327260 uname + + +Details of implementation +------------------------- +fileproto.proto contains the portable Google Protocol Buffers protocol definition. +It could be used as-is to implement a server or a client in any other language, for +example Python or Java. + +fileproto.options contains the nanopb-specific options for the protocol file. This +sets the amount of space allocated for file names when decoding messages. + +common.c/h contains functions that allow nanopb to read and write directly from +network socket. This way there is no need to allocate a separate buffer to store +the message. + +server.c contains the code to open a listening socket, to respond to clients and +to list directory contents. + +client.c contains the code to connect to a server, to send a request and to print +the response message. + +The code is implemented using the POSIX socket api, but it should be easy enough +to port into any other socket api, such as lwip. diff --git a/libs/nanopb/examples/network_server/client.c b/libs/nanopb/examples/network_server/client.c new file mode 100644 index 0000000..00f6dab --- /dev/null +++ b/libs/nanopb/examples/network_server/client.c @@ -0,0 +1,142 @@ +/* This is a simple TCP client that connects to port 1234 and prints a list + * of files in a given directory. + * + * It directly deserializes and serializes messages from network, minimizing + * memory use. + * + * For flexibility, this example is implemented using posix api. + * In a real embedded system you would typically use some other kind of + * a communication and filesystem layer. + */ + +#include <sys/socket.h> +#include <sys/types.h> +#include <netinet/in.h> +#include <unistd.h> +#include <dirent.h> +#include <stdio.h> +#include <string.h> + +#include <pb_encode.h> +#include <pb_decode.h> + +#include "fileproto.pb.h" +#include "common.h" + +/* This callback function will be called once for each filename received + * from the server. The filenames will be printed out immediately, so that + * no memory has to be allocated for them. + */ +bool printfile_callback(pb_istream_t *stream, const pb_field_t *field, void **arg) +{ + FileInfo fileinfo = {}; + + if (!pb_decode(stream, FileInfo_fields, &fileinfo)) + return false; + + printf("%-10lld %s\n", (long long)fileinfo.inode, fileinfo.name); + + return true; +} + +/* This function sends a request to socket 'fd' to list the files in + * directory given in 'path'. The results received from server will + * be printed to stdout. + */ +bool listdir(int fd, char *path) +{ + /* Construct and send the request to server */ + { + ListFilesRequest request = {}; + pb_ostream_t output = pb_ostream_from_socket(fd); + uint8_t zero = 0; + + /* In our protocol, path is optional. If it is not given, + * the server will list the root directory. */ + if (path == NULL) + { + request.has_path = false; + } + else + { + request.has_path = true; + if (strlen(path) + 1 > sizeof(request.path)) + { + fprintf(stderr, "Too long path.\n"); + return false; + } + + strcpy(request.path, path); + } + + /* Encode the request. It is written to the socket immediately + * through our custom stream. */ + if (!pb_encode(&output, ListFilesRequest_fields, &request)) + { + fprintf(stderr, "Encoding failed: %s\n", PB_GET_ERROR(&output)); + return false; + } + + /* We signal the end of request with a 0 tag. */ + pb_write(&output, &zero, 1); + } + + /* Read back the response from server */ + { + ListFilesResponse response = {}; + pb_istream_t input = pb_istream_from_socket(fd); + + /* Give a pointer to our callback function, which will handle the + * filenames as they arrive. */ + response.file.funcs.decode = &printfile_callback; + + if (!pb_decode(&input, ListFilesResponse_fields, &response)) + { + fprintf(stderr, "Decode failed: %s\n", PB_GET_ERROR(&input)); + return false; + } + + /* If the message from server decodes properly, but directory was + * not found on server side, we get path_error == true. */ + if (response.path_error) + { + fprintf(stderr, "Server reported error.\n"); + return false; + } + } + + return true; +} + +int main(int argc, char **argv) +{ + int sockfd; + struct sockaddr_in servaddr; + char *path = NULL; + + if (argc > 1) + path = argv[1]; + + sockfd = socket(AF_INET, SOCK_STREAM, 0); + + /* Connect to server running on localhost:1234 */ + memset(&servaddr, 0, sizeof(servaddr)); + servaddr.sin_family = AF_INET; + servaddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK); + servaddr.sin_port = htons(1234); + + if (connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr)) != 0) + { + perror("connect"); + return 1; + } + + /* Send the directory listing request */ + if (!listdir(sockfd, path)) + return 2; + + /* Close connection */ + close(sockfd); + + return 0; +} diff --git a/libs/nanopb/examples/network_server/common.c b/libs/nanopb/examples/network_server/common.c new file mode 100644 index 0000000..04a5aa8 --- /dev/null +++ b/libs/nanopb/examples/network_server/common.c @@ -0,0 +1,40 @@ +/* Simple binding of nanopb streams to TCP sockets. + */ + +#include <sys/socket.h> +#include <sys/types.h> +#include <pb_encode.h> +#include <pb_decode.h> + +#include "common.h" + +static bool write_callback(pb_ostream_t *stream, const uint8_t *buf, size_t count) +{ + int fd = (intptr_t)stream->state; + return send(fd, buf, count, 0) == count; +} + +static bool read_callback(pb_istream_t *stream, uint8_t *buf, size_t count) +{ + int fd = (intptr_t)stream->state; + int result; + + result = recv(fd, buf, count, MSG_WAITALL); + + if (result == 0) + stream->bytes_left = 0; /* EOF */ + + return result == count; +} + +pb_ostream_t pb_ostream_from_socket(int fd) +{ + pb_ostream_t stream = {&write_callback, (void*)(intptr_t)fd, SIZE_MAX, 0}; + return stream; +} + +pb_istream_t pb_istream_from_socket(int fd) +{ + pb_istream_t stream = {&read_callback, (void*)(intptr_t)fd, SIZE_MAX}; + return stream; +} diff --git a/libs/nanopb/examples/network_server/common.h b/libs/nanopb/examples/network_server/common.h new file mode 100644 index 0000000..8dab3b7 --- /dev/null +++ b/libs/nanopb/examples/network_server/common.h @@ -0,0 +1,9 @@ +#ifndef _PB_EXAMPLE_COMMON_H_ +#define _PB_EXAMPLE_COMMON_H_ + +#include <pb.h> + +pb_ostream_t pb_ostream_from_socket(int fd); +pb_istream_t pb_istream_from_socket(int fd); + +#endif
\ No newline at end of file diff --git a/libs/nanopb/examples/network_server/fileproto.options b/libs/nanopb/examples/network_server/fileproto.options new file mode 100644 index 0000000..29a2ab0 --- /dev/null +++ b/libs/nanopb/examples/network_server/fileproto.options @@ -0,0 +1,13 @@ +# This file defines the nanopb-specific options for the messages defined +# in fileproto.proto. +# +# If you come from high-level programming background, the hardcoded +# maximum lengths may disgust you. However, if your microcontroller only +# has a few kB of ram to begin with, setting reasonable limits for +# filenames is ok. +# +# On the other hand, using the callback interface, it is not necessary +# to set a limit on the number of files in the response. + +ListFilesRequest.path max_size:128 +FileInfo.name max_size:128 diff --git a/libs/nanopb/examples/network_server/fileproto.proto b/libs/nanopb/examples/network_server/fileproto.proto new file mode 100644 index 0000000..5640b8d --- /dev/null +++ b/libs/nanopb/examples/network_server/fileproto.proto @@ -0,0 +1,20 @@ +// This defines protocol for a simple server that lists files. +// +// See also the nanopb-specific options in fileproto.options. + +syntax = "proto2"; + +message ListFilesRequest { + optional string path = 1 [default = "/"]; +} + +message FileInfo { + required uint64 inode = 1; + required string name = 2; +} + +message ListFilesResponse { + optional bool path_error = 1 [default = false]; + repeated FileInfo file = 2; +} + diff --git a/libs/nanopb/examples/network_server/server.c b/libs/nanopb/examples/network_server/server.c new file mode 100644 index 0000000..46a5f38 --- /dev/null +++ b/libs/nanopb/examples/network_server/server.c @@ -0,0 +1,158 @@ +/* This is a simple TCP server that listens on port 1234 and provides lists + * of files to clients, using a protocol defined in file_server.proto. + * + * It directly deserializes and serializes messages from network, minimizing + * memory use. + * + * For flexibility, this example is implemented using posix api. + * In a real embedded system you would typically use some other kind of + * a communication and filesystem layer. + */ + +#include <sys/socket.h> +#include <sys/types.h> +#include <netinet/in.h> +#include <unistd.h> +#include <dirent.h> +#include <stdio.h> +#include <string.h> + +#include <pb_encode.h> +#include <pb_decode.h> + +#include "fileproto.pb.h" +#include "common.h" + +/* This callback function will be called once during the encoding. + * It will write out any number of FileInfo entries, without consuming unnecessary memory. + * This is accomplished by fetching the filenames one at a time and encoding them + * immediately. + */ +bool listdir_callback(pb_ostream_t *stream, const pb_field_t *field, void * const *arg) +{ + DIR *dir = (DIR*) *arg; + struct dirent *file; + FileInfo fileinfo = {}; + + while ((file = readdir(dir)) != NULL) + { + fileinfo.inode = file->d_ino; + strncpy(fileinfo.name, file->d_name, sizeof(fileinfo.name)); + fileinfo.name[sizeof(fileinfo.name) - 1] = '\0'; + + /* This encodes the header for the field, based on the constant info + * from pb_field_t. */ + if (!pb_encode_tag_for_field(stream, field)) + return false; + + /* This encodes the data for the field, based on our FileInfo structure. */ + if (!pb_encode_submessage(stream, FileInfo_fields, &fileinfo)) + return false; + } + + return true; +} + +/* Handle one arriving client connection. + * Clients are expected to send a ListFilesRequest, terminated by a '0'. + * Server will respond with a ListFilesResponse message. + */ +void handle_connection(int connfd) +{ + DIR *directory = NULL; + + /* Decode the message from the client and open the requested directory. */ + { + ListFilesRequest request = {}; + pb_istream_t input = pb_istream_from_socket(connfd); + + if (!pb_decode(&input, ListFilesRequest_fields, &request)) + { + printf("Decode failed: %s\n", PB_GET_ERROR(&input)); + return; + } + + directory = opendir(request.path); + printf("Listing directory: %s\n", request.path); + } + + /* List the files in the directory and transmit the response to client */ + { + ListFilesResponse response = {}; + pb_ostream_t output = pb_ostream_from_socket(connfd); + + if (directory == NULL) + { + perror("opendir"); + + /* Directory was not found, transmit error status */ + response.has_path_error = true; + response.path_error = true; + response.file.funcs.encode = NULL; + } + else + { + /* Directory was found, transmit filenames */ + response.has_path_error = false; + response.file.funcs.encode = &listdir_callback; + response.file.arg = directory; + } + + if (!pb_encode(&output, ListFilesResponse_fields, &response)) + { + printf("Encoding failed: %s\n", PB_GET_ERROR(&output)); + } + } + + if (directory != NULL) + closedir(directory); +} + +int main(int argc, char **argv) +{ + int listenfd, connfd; + struct sockaddr_in servaddr; + int reuse = 1; + + /* Listen on localhost:1234 for TCP connections */ + listenfd = socket(AF_INET, SOCK_STREAM, 0); + setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse)); + + memset(&servaddr, 0, sizeof(servaddr)); + servaddr.sin_family = AF_INET; + servaddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK); + servaddr.sin_port = htons(1234); + if (bind(listenfd, (struct sockaddr*)&servaddr, sizeof(servaddr)) != 0) + { + perror("bind"); + return 1; + } + + if (listen(listenfd, 5) != 0) + { + perror("listen"); + return 1; + } + + for(;;) + { + /* Wait for a client */ + connfd = accept(listenfd, NULL, NULL); + + if (connfd < 0) + { + perror("accept"); + return 1; + } + + printf("Got connection.\n"); + + handle_connection(connfd); + + printf("Closing connection.\n"); + + close(connfd); + } + + return 0; +} diff --git a/libs/nanopb/examples/simple/Makefile b/libs/nanopb/examples/simple/Makefile new file mode 100644 index 0000000..970a865 --- /dev/null +++ b/libs/nanopb/examples/simple/Makefile @@ -0,0 +1,22 @@ +# Include the nanopb provided Makefile rules +include ../../extra/nanopb.mk + +# Compiler flags to enable all warnings & debug info +CFLAGS = -Wall -Werror -g -O0 +CFLAGS += -I$(NANOPB_DIR) + +# C source code files that are required +CSRC = simple.c # The main program +CSRC += simple.pb.c # The compiled protocol definition +CSRC += $(NANOPB_DIR)/pb_encode.c # The nanopb encoder +CSRC += $(NANOPB_DIR)/pb_decode.c # The nanopb decoder +CSRC += $(NANOPB_DIR)/pb_common.c # The nanopb common parts + +# Build rule for the main program +simple: $(CSRC) + $(CC) $(CFLAGS) -osimple $(CSRC) + +# Build rule for the protocol +simple.pb.c: simple.proto + $(PROTOC) $(PROTOC_OPTS) --nanopb_out=. simple.proto + diff --git a/libs/nanopb/examples/simple/README.txt b/libs/nanopb/examples/simple/README.txt new file mode 100644 index 0000000..ee77bfc --- /dev/null +++ b/libs/nanopb/examples/simple/README.txt @@ -0,0 +1,29 @@ +Nanopb example "simple" +======================= + +This example demonstrates the very basic use of nanopb. It encodes and +decodes a simple message. + +The code uses four different API functions: + + * pb_ostream_from_buffer() to declare the output buffer that is to be used + * pb_encode() to encode a message + * pb_istream_from_buffer() to declare the input buffer that is to be used + * pb_decode() to decode a message + +Example usage +------------- + +On Linux, simply type "make" to build the example. After that, you can +run it with the command: ./simple + +On other platforms, you first have to compile the protocol definition using +the following command:: + + ../../generator-bin/protoc --nanopb_out=. simple.proto + +After that, add the following four files to your project and compile: + + simple.c simple.pb.c pb_encode.c pb_decode.c + + diff --git a/libs/nanopb/examples/simple/simple.c b/libs/nanopb/examples/simple/simple.c new file mode 100644 index 0000000..1f6b137 --- /dev/null +++ b/libs/nanopb/examples/simple/simple.c @@ -0,0 +1,71 @@ +#include <stdio.h> +#include <pb_encode.h> +#include <pb_decode.h> +#include "simple.pb.h" + +int main() +{ + /* This is the buffer where we will store our message. */ + uint8_t buffer[128]; + size_t message_length; + bool status; + + /* Encode our message */ + { + /* Allocate space on the stack to store the message data. + * + * Nanopb generates simple struct definitions for all the messages. + * - check out the contents of simple.pb.h! + * It is a good idea to always initialize your structures + * so that you do not have garbage data from RAM in there. + */ + SimpleMessage message = SimpleMessage_init_zero; + + /* Create a stream that will write to our buffer. */ + pb_ostream_t stream = pb_ostream_from_buffer(buffer, sizeof(buffer)); + + /* Fill in the lucky number */ + message.lucky_number = 13; + + /* Now we are ready to encode the message! */ + status = pb_encode(&stream, SimpleMessage_fields, &message); + message_length = stream.bytes_written; + + /* Then just check for any errors.. */ + if (!status) + { + printf("Encoding failed: %s\n", PB_GET_ERROR(&stream)); + return 1; + } + } + + /* Now we could transmit the message over network, store it in a file or + * wrap it to a pigeon's leg. + */ + + /* But because we are lazy, we will just decode it immediately. */ + + { + /* Allocate space for the decoded message. */ + SimpleMessage message = SimpleMessage_init_zero; + + /* Create a stream that reads from the buffer. */ + pb_istream_t stream = pb_istream_from_buffer(buffer, message_length); + + /* Now we are ready to decode the message. */ + status = pb_decode(&stream, SimpleMessage_fields, &message); + + /* Check for errors... */ + if (!status) + { + printf("Decoding failed: %s\n", PB_GET_ERROR(&stream)); + return 1; + } + + /* Print the data contained in the message. */ + printf("Your lucky number was %d!\n", message.lucky_number); + } + + return 0; +} + diff --git a/libs/nanopb/examples/simple/simple.proto b/libs/nanopb/examples/simple/simple.proto new file mode 100644 index 0000000..5c73a3b --- /dev/null +++ b/libs/nanopb/examples/simple/simple.proto @@ -0,0 +1,9 @@ +// A very simple protocol definition, consisting of only +// one message. + +syntax = "proto2"; + +message SimpleMessage { + required int32 lucky_number = 1; +} + diff --git a/libs/nanopb/examples/using_double_on_avr/Makefile b/libs/nanopb/examples/using_double_on_avr/Makefile new file mode 100644 index 0000000..874a64b --- /dev/null +++ b/libs/nanopb/examples/using_double_on_avr/Makefile @@ -0,0 +1,24 @@ +# Include the nanopb provided Makefile rules +include ../../extra/nanopb.mk + +# Compiler flags to enable all warnings & debug info +CFLAGS = -Wall -Werror -g -O0 +CFLAGS += -I$(NANOPB_DIR) + +all: run_tests + +.SUFFIXES: + +clean: + rm -f test_conversions encode_double decode_double doubleproto.pb.c doubleproto.pb.h + +test_conversions: test_conversions.c double_conversion.c + $(CC) $(CFLAGS) -o $@ $^ + +%: %.c double_conversion.c doubleproto.pb.c + $(CC) $(CFLAGS) -o $@ $^ $(NANOPB_CORE) + +run_tests: test_conversions encode_double decode_double + ./test_conversions + ./encode_double | ./decode_double + diff --git a/libs/nanopb/examples/using_double_on_avr/README.txt b/libs/nanopb/examples/using_double_on_avr/README.txt new file mode 100644 index 0000000..d9fcdfc --- /dev/null +++ b/libs/nanopb/examples/using_double_on_avr/README.txt @@ -0,0 +1,25 @@ +Nanopb example "using_double_on_avr" +==================================== + +Some processors/compilers, such as AVR-GCC, do not support the double +datatype. Instead, they have sizeof(double) == 4. Because protocol +binary format uses the double encoding directly, this causes trouble +if the protocol in .proto requires double fields. + +This directory contains a solution to this problem. It uses uint64_t +to store the raw wire values, because its size is correct on all +platforms. The file double_conversion.c provides functions that +convert these values to/from floats, without relying on compiler +support. + +To use this method, you need to make some modifications to your code: + +1) Change all 'double' fields into 'fixed64' in the .proto. + +2) Whenever writing to a 'double' field, use float_to_double(). + +3) Whenever reading a 'double' field, use double_to_float(). + +The conversion routines are as accurate as the float datatype can +be. Furthermore, they should handle all special values (NaN, inf, denormalized +numbers) correctly. There are testcases in test_conversions.c. diff --git a/libs/nanopb/examples/using_double_on_avr/decode_double.c b/libs/nanopb/examples/using_double_on_avr/decode_double.c new file mode 100644 index 0000000..5802eca --- /dev/null +++ b/libs/nanopb/examples/using_double_on_avr/decode_double.c @@ -0,0 +1,33 @@ +/* Decodes a double value into a float variable. + * Used to read double values with AVR code, which doesn't support double directly. + */ + +#include <stdio.h> +#include <pb_decode.h> +#include "double_conversion.h" +#include "doubleproto.pb.h" + +int main() +{ + uint8_t buffer[32]; + size_t count = fread(buffer, 1, sizeof(buffer), stdin); + pb_istream_t stream = pb_istream_from_buffer(buffer, count); + + AVRDoubleMessage message; + pb_decode(&stream, AVRDoubleMessage_fields, &message); + + float v1 = double_to_float(message.field1); + float v2 = double_to_float(message.field2); + + printf("Values: %f %f\n", v1, v2); + + if (v1 == 1234.5678f && + v2 == 0.00001f) + { + return 0; + } + else + { + return 1; + } +} diff --git a/libs/nanopb/examples/using_double_on_avr/double_conversion.c b/libs/nanopb/examples/using_double_on_avr/double_conversion.c new file mode 100644 index 0000000..cf79b9a --- /dev/null +++ b/libs/nanopb/examples/using_double_on_avr/double_conversion.c @@ -0,0 +1,123 @@ +/* Conversion routines for platforms that do not support 'double' directly. */ + +#include "double_conversion.h" +#include <math.h> + +typedef union { + float f; + uint32_t i; +} conversion_t; + +/* Note: IEE 754 standard specifies float formats as follows: + * Single precision: sign, 8-bit exp, 23-bit frac. + * Double precision: sign, 11-bit exp, 52-bit frac. + */ + +uint64_t float_to_double(float value) +{ + conversion_t in; + in.f = value; + uint8_t sign; + int16_t exponent; + uint64_t mantissa; + + /* Decompose input value */ + sign = (in.i >> 31) & 1; + exponent = ((in.i >> 23) & 0xFF) - 127; + mantissa = in.i & 0x7FFFFF; + + if (exponent == 128) + { + /* Special value (NaN etc.) */ + exponent = 1024; + } + else if (exponent == -127) + { + if (!mantissa) + { + /* Zero */ + exponent = -1023; + } + else + { + /* Denormalized */ + mantissa <<= 1; + while (!(mantissa & 0x800000)) + { + mantissa <<= 1; + exponent--; + } + mantissa &= 0x7FFFFF; + } + } + + /* Combine fields */ + mantissa <<= 29; + mantissa |= (uint64_t)(exponent + 1023) << 52; + mantissa |= (uint64_t)sign << 63; + + return mantissa; +} + +float double_to_float(uint64_t value) +{ + uint8_t sign; + int16_t exponent; + uint32_t mantissa; + conversion_t out; + + /* Decompose input value */ + sign = (value >> 63) & 1; + exponent = ((value >> 52) & 0x7FF) - 1023; + mantissa = (value >> 28) & 0xFFFFFF; /* Highest 24 bits */ + + /* Figure if value is in range representable by floats. */ + if (exponent == 1024) + { + /* Special value */ + exponent = 128; + } + else if (exponent > 127) + { + /* Too large */ + if (sign) + return -INFINITY; + else + return INFINITY; + } + else if (exponent < -150) + { + /* Too small */ + if (sign) + return -0.0f; + else + return 0.0f; + } + else if (exponent < -126) + { + /* Denormalized */ + mantissa |= 0x1000000; + mantissa >>= (-126 - exponent); + exponent = -127; + } + + /* Round off mantissa */ + mantissa = (mantissa + 1) >> 1; + + /* Check if mantissa went over 2.0 */ + if (mantissa & 0x800000) + { + exponent += 1; + mantissa &= 0x7FFFFF; + mantissa >>= 1; + } + + /* Combine fields */ + out.i = mantissa; + out.i |= (uint32_t)(exponent + 127) << 23; + out.i |= (uint32_t)sign << 31; + + return out.f; +} + + diff --git a/libs/nanopb/examples/using_double_on_avr/double_conversion.h b/libs/nanopb/examples/using_double_on_avr/double_conversion.h new file mode 100644 index 0000000..62b6a8a --- /dev/null +++ b/libs/nanopb/examples/using_double_on_avr/double_conversion.h @@ -0,0 +1,26 @@ +/* AVR-GCC does not have real double datatype. Instead its double + * is equal to float, i.e. 32 bit value. If you need to communicate + * with other systems that use double in their .proto files, you + * need to do some conversion. + * + * These functions use bitwise operations to mangle floats into doubles + * and then store them in uint64_t datatype. + */ + +#ifndef DOUBLE_CONVERSION +#define DOUBLE_CONVERSION + +#include <stdint.h> + +/* Convert native 4-byte float into a 8-byte double. */ +extern uint64_t float_to_double(float value); + +/* Convert 8-byte double into native 4-byte float. + * Values are rounded to nearest, 0.5 away from zero. + * Overflowing values are converted to Inf or -Inf. + */ +extern float double_to_float(uint64_t value); + + +#endif + diff --git a/libs/nanopb/examples/using_double_on_avr/doubleproto.proto b/libs/nanopb/examples/using_double_on_avr/doubleproto.proto new file mode 100644 index 0000000..72d3f9c --- /dev/null +++ b/libs/nanopb/examples/using_double_on_avr/doubleproto.proto @@ -0,0 +1,15 @@ +// A message containing doubles, as used by other applications. +syntax = "proto2"; + +message DoubleMessage { + required double field1 = 1; + required double field2 = 2; +} + +// A message containing doubles, but redefined using uint64_t. +// For use in AVR code. +message AVRDoubleMessage { + required fixed64 field1 = 1; + required fixed64 field2 = 2; +} + diff --git a/libs/nanopb/examples/using_double_on_avr/encode_double.c b/libs/nanopb/examples/using_double_on_avr/encode_double.c new file mode 100644 index 0000000..cd532d4 --- /dev/null +++ b/libs/nanopb/examples/using_double_on_avr/encode_double.c @@ -0,0 +1,25 @@ +/* Encodes a float value into a double on the wire. + * Used to emit doubles from AVR code, which doesn't support double directly. + */ + +#include <stdio.h> +#include <pb_encode.h> +#include "double_conversion.h" +#include "doubleproto.pb.h" + +int main() +{ + AVRDoubleMessage message = { + float_to_double(1234.5678f), + float_to_double(0.00001f) + }; + + uint8_t buffer[32]; + pb_ostream_t stream = pb_ostream_from_buffer(buffer, sizeof(buffer)); + + pb_encode(&stream, AVRDoubleMessage_fields, &message); + fwrite(buffer, 1, stream.bytes_written, stdout); + + return 0; +} + diff --git a/libs/nanopb/examples/using_double_on_avr/test_conversions.c b/libs/nanopb/examples/using_double_on_avr/test_conversions.c new file mode 100644 index 0000000..22620a6 --- /dev/null +++ b/libs/nanopb/examples/using_double_on_avr/test_conversions.c @@ -0,0 +1,56 @@ +#include "double_conversion.h" +#include <math.h> +#include <stdio.h> + +static const double testvalues[] = { + 0.0, -0.0, 0.1, -0.1, + M_PI, -M_PI, 123456.789, -123456.789, + INFINITY, -INFINITY, NAN, INFINITY - INFINITY, + 1e38, -1e38, 1e39, -1e39, + 1e-38, -1e-38, 1e-39, -1e-39, + 3.14159e-37,-3.14159e-37, 3.14159e-43, -3.14159e-43, + 1e-60, -1e-60, 1e-45, -1e-45, + 0.99999999999999, -0.99999999999999, 127.999999999999, -127.999999999999 +}; + +#define TESTVALUES_COUNT (sizeof(testvalues)/sizeof(testvalues[0])) + +int main() +{ + int status = 0; + int i; + for (i = 0; i < TESTVALUES_COUNT; i++) + { + double orig = testvalues[i]; + float expected_float = (float)orig; + double expected_double = (double)expected_float; + + float got_float = double_to_float(*(uint64_t*)&orig); + uint64_t got_double = float_to_double(got_float); + + uint32_t e1 = *(uint32_t*)&expected_float; + uint32_t g1 = *(uint32_t*)&got_float; + uint64_t e2 = *(uint64_t*)&expected_double; + uint64_t g2 = got_double; + + if (g1 != e1) + { + printf("%3d double_to_float fail: %08x != %08x\n", i, g1, e1); + status = 1; + } + + if (g2 != e2) + { + printf("%3d float_to_double fail: %016llx != %016llx\n", i, + (unsigned long long)g2, + (unsigned long long)e2); + status = 1; + } + } + + return status; +} + + + + diff --git a/libs/nanopb/examples/using_union_messages/Makefile b/libs/nanopb/examples/using_union_messages/Makefile new file mode 100644 index 0000000..66396a0 --- /dev/null +++ b/libs/nanopb/examples/using_union_messages/Makefile @@ -0,0 +1,20 @@ +# Include the nanopb provided Makefile rules +include ../../extra/nanopb.mk + +# Compiler flags to enable all warnings & debug info +CFLAGS = -ansi -Wall -Werror -g -O0 +CFLAGS += -I$(NANOPB_DIR) + +all: encode decode + ./encode 1 | ./decode + ./encode 2 | ./decode + ./encode 3 | ./decode + +.SUFFIXES: + +clean: + rm -f encode unionproto.pb.h unionproto.pb.c + +%: %.c unionproto.pb.c + $(CC) $(CFLAGS) -o $@ $^ $(NANOPB_CORE) + diff --git a/libs/nanopb/examples/using_union_messages/README.txt b/libs/nanopb/examples/using_union_messages/README.txt new file mode 100644 index 0000000..7a1e75d --- /dev/null +++ b/libs/nanopb/examples/using_union_messages/README.txt @@ -0,0 +1,52 @@ +Nanopb example "using_union_messages" +===================================== + +Union messages is a common technique in Google Protocol Buffers used to +represent a group of messages, only one of which is passed at a time. +It is described in Google's documentation: +https://developers.google.com/protocol-buffers/docs/techniques#union + +This directory contains an example on how to encode and decode union messages +with minimal memory usage. Usually, nanopb would allocate space to store +all of the possible messages at the same time, even though at most one of +them will be used at a time. + +By using some of the lower level nanopb APIs, we can manually generate the +top level message, so that we only need to allocate the one submessage that +we actually want. Similarly when decoding, we can manually read the tag of +the top level message, and only then allocate the memory for the submessage +after we already know its type. + + +Example usage +------------- + +Type `make` to run the example. It will build it and run commands like +following: + +./encode 1 | ./decode +Got MsgType1: 42 +./encode 2 | ./decode +Got MsgType2: true +./encode 3 | ./decode +Got MsgType3: 3 1415 + +This simply demonstrates that the "decode" program has correctly identified +the type of the received message, and managed to decode it. + + +Details of implementation +------------------------- + +unionproto.proto contains the protocol used in the example. It consists of +three messages: MsgType1, MsgType2 and MsgType3, which are collected together +into UnionMessage. + +encode.c takes one command line argument, which should be a number 1-3. It +then fills in and encodes the corresponding message, and writes it to stdout. + +decode.c reads a UnionMessage from stdin. Then it calls the function +decode_unionmessage_type() to determine the type of the message. After that, +the corresponding message is decoded and the contents of it printed to the +screen. + diff --git a/libs/nanopb/examples/using_union_messages/decode.c b/libs/nanopb/examples/using_union_messages/decode.c new file mode 100644 index 0000000..b9f4af5 --- /dev/null +++ b/libs/nanopb/examples/using_union_messages/decode.c @@ -0,0 +1,96 @@ +/* This program reads a message from stdin, detects its type and decodes it. + */ + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> + +#include <pb_decode.h> +#include "unionproto.pb.h" + +/* This function reads manually the first tag from the stream and finds the + * corresponding message type. It doesn't yet decode the actual message. + * + * Returns a pointer to the MsgType_fields array, as an identifier for the + * message type. Returns null if the tag is of unknown type or an error occurs. + */ +const pb_field_t* decode_unionmessage_type(pb_istream_t *stream) +{ + pb_wire_type_t wire_type; + uint32_t tag; + bool eof; + + while (pb_decode_tag(stream, &wire_type, &tag, &eof)) + { + if (wire_type == PB_WT_STRING) + { + const pb_field_t *field; + for (field = UnionMessage_fields; field->tag != 0; field++) + { + if (field->tag == tag && (field->type & PB_LTYPE_SUBMESSAGE)) + { + /* Found our field. */ + return field->ptr; + } + } + } + + /* Wasn't our field.. */ + pb_skip_field(stream, wire_type); + } + + return NULL; +} + +bool decode_unionmessage_contents(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct) +{ + pb_istream_t substream; + bool status; + if (!pb_make_string_substream(stream, &substream)) + return false; + + status = pb_decode(&substream, fields, dest_struct); + pb_close_string_substream(stream, &substream); + return status; +} + +int main() +{ + /* Read the data into buffer */ + uint8_t buffer[512]; + size_t count = fread(buffer, 1, sizeof(buffer), stdin); + pb_istream_t stream = pb_istream_from_buffer(buffer, count); + + const pb_field_t *type = decode_unionmessage_type(&stream); + bool status = false; + + if (type == MsgType1_fields) + { + MsgType1 msg = {}; + status = decode_unionmessage_contents(&stream, MsgType1_fields, &msg); + printf("Got MsgType1: %d\n", msg.value); + } + else if (type == MsgType2_fields) + { + MsgType2 msg = {}; + status = decode_unionmessage_contents(&stream, MsgType2_fields, &msg); + printf("Got MsgType2: %s\n", msg.value ? "true" : "false"); + } + else if (type == MsgType3_fields) + { + MsgType3 msg = {}; + status = decode_unionmessage_contents(&stream, MsgType3_fields, &msg); + printf("Got MsgType3: %d %d\n", msg.value1, msg.value2); + } + + if (!status) + { + printf("Decode failed: %s\n", PB_GET_ERROR(&stream)); + return 1; + } + + return 0; +} + + + diff --git a/libs/nanopb/examples/using_union_messages/encode.c b/libs/nanopb/examples/using_union_messages/encode.c new file mode 100644 index 0000000..e124bf9 --- /dev/null +++ b/libs/nanopb/examples/using_union_messages/encode.c @@ -0,0 +1,85 @@ +/* This program takes a command line argument and encodes a message in + * one of MsgType1, MsgType2 or MsgType3. + */ + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> + +#include <pb_encode.h> +#include "unionproto.pb.h" + +/* This function is the core of the union encoding process. It handles + * the top-level pb_field_t array manually, in order to encode a correct + * field tag before the message. The pointer to MsgType_fields array is + * used as an unique identifier for the message type. + */ +bool encode_unionmessage(pb_ostream_t *stream, const pb_field_t messagetype[], const void *message) +{ + const pb_field_t *field; + for (field = UnionMessage_fields; field->tag != 0; field++) + { + if (field->ptr == messagetype) + { + /* This is our field, encode the message using it. */ + if (!pb_encode_tag_for_field(stream, field)) + return false; + + return pb_encode_submessage(stream, messagetype, message); + } + } + + /* Didn't find the field for messagetype */ + return false; +} + +int main(int argc, char **argv) +{ + if (argc != 2) + { + fprintf(stderr, "Usage: %s (1|2|3)\n", argv[0]); + return 1; + } + + uint8_t buffer[512]; + pb_ostream_t stream = pb_ostream_from_buffer(buffer, sizeof(buffer)); + + bool status = false; + int msgtype = atoi(argv[1]); + if (msgtype == 1) + { + /* Send message of type 1 */ + MsgType1 msg = {42}; + status = encode_unionmessage(&stream, MsgType1_fields, &msg); + } + else if (msgtype == 2) + { + /* Send message of type 2 */ + MsgType2 msg = {true}; + status = encode_unionmessage(&stream, MsgType2_fields, &msg); + } + else if (msgtype == 3) + { + /* Send message of type 3 */ + MsgType3 msg = {3, 1415}; + status = encode_unionmessage(&stream, MsgType3_fields, &msg); + } + else + { + fprintf(stderr, "Unknown message type: %d\n", msgtype); + return 2; + } + + if (!status) + { + fprintf(stderr, "Encoding failed!\n"); + return 3; + } + else + { + fwrite(buffer, 1, stream.bytes_written, stdout); + return 0; /* Success */ + } +} + + diff --git a/libs/nanopb/examples/using_union_messages/unionproto.proto b/libs/nanopb/examples/using_union_messages/unionproto.proto new file mode 100644 index 0000000..209df0d --- /dev/null +++ b/libs/nanopb/examples/using_union_messages/unionproto.proto @@ -0,0 +1,32 @@ +// This is an example of how to handle 'union' style messages +// with nanopb, without allocating memory for all the message types. +// +// There is no official type in Protocol Buffers for describing unions, +// but they are commonly implemented by filling out exactly one of +// several optional fields. + +syntax = "proto2"; + +message MsgType1 +{ + required int32 value = 1; +} + +message MsgType2 +{ + required bool value = 1; +} + +message MsgType3 +{ + required int32 value1 = 1; + required int32 value2 = 2; +} + +message UnionMessage +{ + optional MsgType1 msg1 = 1; + optional MsgType2 msg2 = 2; + optional MsgType3 msg3 = 3; +} + |