[PATCH c-hglib] Initial commit
Iulian Stana
julian.stana at gmail.com
Mon Jul 1 16:32:24 CDT 2013
This is a draft of my work for c-hglib up to now, I am sending this to the
list
for public review (even if this is not a patch for the core mercurial). I am
sure that the main developers following my work (Matt, Giovanni,
Pierre-Yves,
Idan and others) will have important remarks on the architecture and on the
style, and I prefer to solicit those feedback sooner than later.
I will try to not abuse of this list and to use it just for important
commits.
2013/7/2 Iulian Stana <julian.stana at gmail.com>
> # HG changeset patch
> # User Iulian Stana <julian.stana at gmail.com>
> # Date 1372688980 -10800
> # Mon Jul 01 17:29:40 2013 +0300
> # Node ID 815459ad3e8f3b979084d621729fa189acd9c348
> # Parent 0000000000000000000000000000000000000000
> Initial commit
>
> Level 0 : raw level
>
> "pass a raw command string, get unparsed results"
>
> Establish a connection between hgclient and mercurial command server.
> After the connection has been established, the messages were exchanged
> with the
> purpose of verification. In the main file will be found a short example.
>
> I've followed some of Matt's remarks:
>
> s/chg/hg_/, make sure everything is prefixed
>
> Also, the prototypes all need to be in the header.
>
> Make sure your char args are char *.
>
> You have exactly open/close in your .h file. The example in my email has
> open/close/command/read. You're not going to be able to do useful work
> with less
> than that. Note that I specifically chose hg log as my example because it's
> likely to generate megabytes of output: you can't simply return it all in
> one
> call.
>
> I've also change:
> - the data structure name from "client" to "handle"
> - the data structure name from "channel" to "header"
> - the name of readchannel function to readheader
> - some of the return statements
>
> I've also erase the mercurial commands for this phase. I'll come back later
> with a better aproach.
>
> diff --git a/hglib/Makefile b/hglib/Makefile
> new file mode 100644
> --- /dev/null
> +++ b/hglib/Makefile
> @@ -0,0 +1,19 @@
> +CC = gcc
> +CFLAGS = -Wall -g
> +TARGET = main
> +
> +build: main
> +
> +main: main.c utils.o client.o
> + $(CC) $(CFLAGS) utils.o client.o -o $(TARGET) main.c
> +
> +client.o: client.c
> + $(CC) $(CFLAGS) -c client.c
> +
> +utils.o: utils.c
> + $(CC) $(CFLAGS) -c utils.c
> +
> +.PHONY: clean
> +
> +clean:
> + rm -f *.o *~ $(TARGET)
> diff --git a/hglib/client.c b/hglib/client.c
> new file mode 100644
> --- /dev/null
> +++ b/hglib/client.c
> @@ -0,0 +1,144 @@
> +#include <sys/types.h>
> +#include <stdlib.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include <fcntl.h>
> +
> +#include "client.h"
> +#include "utils.h"
> +
> +#define HGPATH "hg"
> +
> +struct hg_handle{
> + int wpipe[2];
> + int rpipe[2];
> + pid_t childpid;
> +
> + #define p_read rpipe[0]
> + #define c_write rpipe[1]
> + #define c_read wpipe[0]
> + #define p_write wpipe[1]
> +};
> +
> +/*
> + * Read the channel and the datasize into the header structure.
> + * */
> +hg_header* readheader(hg_handle *handle)
> +{
> + hg_header *ch = malloc(sizeof(hg_header));
> + uint32_t length;
> + char ch_char;
> +
> + read(handle->p_read, &ch_char, 1);
> + read(handle->p_read, &length, sizeof(uint32_t));
> + ch->channel = ch_char;
> + ch->length = swap_uint32(length);
> +
> + return ch;
> +}
> +
> +/*
> + * Read the hello message, the server sends when started
> + * Watch for a bad server starting.
> + * */
> +int readhello(hg_handle *handle)
> +{
> + hg_header *ch = readheader(handle);
> + char *buffer = malloc(ch->length);
> + read(handle->p_read, buffer, ch->length);
> +
> + //TODO: Make a verification !!!
> +
> + printf("%c%u", ch->channel, ch->length);
> + printf("%s\n", buffer);
> + free(ch);
> + free(buffer);
> +
> + return 0;
> +}
> +
> +/*
> + * Send the "command" to the cmdserver through handle.
> + * */
> +int hg_rawcommand(hg_handle *handle, const char *command)
> +{
> + char runcommand[] = "runcommand\n";
> + uint32_t cmdsize = swap_uint32(strlen(command));
> + write(handle->p_write, runcommand, strlen(runcommand));
> + write(handle->p_write, &cmdsize, sizeof(uint32_t));
> + write(handle->p_write, command, strlen(command));
> +
> + return 0;
> +}
> +
> +/*
> + * Receive unparse data from the server through handle.
> + * Put the data into the buffer.
> + * */
> +int hg_rawread(hg_handle *handle, char *buffer, size_t sizebuff)
> +{
> + hg_header *ch = readheader(handle);
> + int length = ch->length;
> +
> + if(ch->channel == 'r'){
> + free(ch);
> + return 0;
> + }
> + else{
> + read(handle->p_read, buffer, ch->length);
> + buffer[ch->length] = '\0';
> + free(ch);
> + return length;
> + }
> +}
> +
> +/*
> + * Create the connection with the mercurial cmdserver
> + * return the handle for this connection
> + * */
> +hg_handle* hg_open(const char *path, char *encoding, char *configs)
> +{
> + hg_handle *handle = malloc(sizeof(hg_handle));
> + char command[100];
> +
> + sprintf(command,"%s serve --cmdserver pipe --config
> ui.interactive=True",
> + HGPATH);
> +
> + if(path)
> + sprintf(command, "%s -R %s", command, path);
> +
> + if(pipe(handle->wpipe) < 0 || pipe(handle->rpipe) < 0){
> + printf("The connection failed\n");
> + }
> +
> + if((handle->childpid = fork()) < 0 ){
> + printf("Fork failed\n");
> + }else if( handle->childpid == 0){ //child
> + close(handle->p_write);
> + close(handle->p_read);
> + dup2(handle->c_read, STDIN_FILENO); close(handle->c_read);
> + dup2(handle->c_write, STDOUT_FILENO); close(handle->c_write);
> + execl("/bin/sh", "sh", "-c", command, NULL);
> +
> + }else{ //parent
> + close(handle->c_read);
> + close(handle->c_write);
> + }
> +
> + readhello(handle);
> +
> + return handle;
> +}
> +
> +/*
> + * Close the connection for a specific handle.
> + * */
> +int hg_close(hg_handle *handle)
> +{
> + close(handle->p_read);
> + close(handle->p_write);
> + free(handle);
> +
> + return 0;
> +}
> diff --git a/hglib/client.h b/hglib/client.h
> new file mode 100644
> --- /dev/null
> +++ b/hglib/client.h
> @@ -0,0 +1,37 @@
> +#ifndef _CLIENT_H_
> +#define _CLIENT_H_
> +#include <stdint.h>
> +
> +
> +struct hg_handle;
> +typedef struct hg_handle hg_handle;
> +
> +typedef struct hg_header{
> + char channel;
> + uint32_t length;
> +} hg_header;
> +
> +/*
> + * Create the connection with the mercurial cmdserver
> + * return the handle for this connection
> + * */
> +hg_handle* hg_open(const char *path, char *encoding, char *configs);
> +
> +/*
> + * Close the connection for a specific handle.
> + * */
> +int hg_close(hg_handle *handle);
> +
> +/*
> + * Send the "command" to the cmdserver through handle.
> + * */
> +int hg_rawcommand(hg_handle *handle, const char *command);
> +
> +/*
> + * Receive unparse data from the server through handle.
> + * Put the data into the buffer.
> + * */
> +int hg_rawread(hg_handle *handle, char *buffer, size_t sizebuff);
> +
> +
> +#endif
> diff --git a/hglib/main.c b/hglib/main.c
> new file mode 100644
> --- /dev/null
> +++ b/hglib/main.c
> @@ -0,0 +1,21 @@
> +#include <stdio.h>
> +
> +#include "client.h"
> +
> +
> +int main(int argc, char ** argv)
> +{
> + char buffer[4096];
> + hg_handle* handle = hg_open(NULL, "", "");
> +
> + printf("\n\n");
> + hg_rawcommand(handle, "log");
> +
> + while(hg_rawread(handle, buffer, 4096)){
> + printf("%s", buffer);
> + }
> +
> + hg_close(handle);
> +
> + return 0;
> +}
> diff --git a/hglib/utils.c b/hglib/utils.c
> new file mode 100644
> --- /dev/null
> +++ b/hglib/utils.c
> @@ -0,0 +1,13 @@
> +#include<stdint.h>
> +#include<stdlib.h>
> +
> +#include "utils.h"
> +
> +void cmdbuilder(char **arg, size_t argsize);
> +
> +//! Byte swap unsigned int
> +uint32_t swap_uint32( uint32_t val )
> +{
> + val = ((val << 8) & 0xFF00FF00 ) | ((val >> 8) & 0xFF00FF );
> + return (val << 16) | (val >> 16);
> +}
> diff --git a/hglib/utils.h b/hglib/utils.h
> new file mode 100644
> --- /dev/null
> +++ b/hglib/utils.h
> @@ -0,0 +1,26 @@
> +#ifndef _UTILS_CHG_H_
> +#define _UTILS_CHG_H_
> +
> +#include<stdint.h>
> +#include<stdlib.h>
> +/*
> + * Build the command arguments.
> + * */
> +void cmdbuilder(char **arg, size_t argsize);
> +
> +uint32_t swap_uint32( uint32_t val );
> +
> +/* useful macro for handling error codes */
> +#define DIE(assertion, call_description) \
> + do { \
> + if (assertion) { \
> + fprintf(stderr, "(%s, %d): ", \
> + __FILE__, __LINE__); \
> + perror(call_description); \
> + exit(EXIT_FAILURE); \
> + } \
> + } while(0)
> +
> +
> +
> +#endif
>
--
O zi buna,
Iulian
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