Starting on conversion to c. Program exec, buffers..

10 files changed, 299 insertions, 5 deletions

diff --git a/.gitignore b/.gitignore
index 0daa041..c65a4e2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 .vscode/
-__pycache__
\ No newline at end of file
+__pycache__
+automedia
diff --git a/alloc.c b/alloc.c
new file mode 100644
index 0000000..dca69b5
--- /dev/null
+++ b/alloc.c
@@ -0,0 +1,20 @@
+#include "alloc.h"
+#include <stdio.h>
+
+void* alloc_or_crash(size_t size) {
+    void *mem = malloc(size);
+    if(!mem) {
+        fprintf(stderr, "Error: failed to allocate %zu bytes\n", size);
+        abort();
+    }
+    return mem;
+}
+
+void* realloc_or_crash(void *mem, size_t new_size) {
+    void *new_mem = realloc(mem, new_size);
+    if(!new_mem) {
+        fprintf(stderr, "Error: failed to reallocate %p to size %zu\n", mem, new_size);
+        abort();
+    }
+    return new_mem;
+}
diff --git a/alloc.h b/alloc.h
new file mode 100644
index 0000000..e8c6c85
--- /dev/null
+++ b/alloc.h
@@ -0,0 +1,10 @@
+#ifndef ALLOC_H
+#define ALLOC_H
+
+#include <stddef.h>
+#include <stdlib.h>
+
+void* alloc_or_crash(size_t size);
+void* realloc_or_crash(void *mem, size_t new_size);
+
+#endif
diff --git a/automedia b/automedia
deleted file mode 100755
index e6e35a1..0000000
--- a/automedia
+++ /dev/null
@@ -1,4 +0,0 @@
-#!/bin/sh
-
-cd /usr/share/automedia
-./automedia.py "$@"
diff --git a/buffer.c b/buffer.c
new file mode 100644
index 0000000..879a62b
--- /dev/null
+++ b/buffer.c
@@ -0,0 +1,54 @@
+#include "buffer.h"
+#include "alloc.h"
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+void buffer_init(Buffer *self) {
+    self->data = NULL;
+    self->size = 0;
+    self->capacity = 0;
+}
+
+void buffer_deinit(Buffer *self) {
+    free(self->data);
+    self->size = 0;
+    self->capacity = 0;
+}
+
+static void buffer_ensure_capacity(Buffer *self, size_t new_size) {
+    size_t new_capacity = self->capacity;
+    if(new_size <= self->capacity)
+        return;
+
+    if(new_capacity == 0)
+        new_capacity = 8;
+    
+    while(new_capacity < new_size) {
+        /* new_capacity *= 1.5 */
+        new_capacity += (new_capacity >> 1);
+    }
+
+    self->data = realloc_or_crash(self->data, new_capacity);
+    self->capacity = new_capacity;
+}
+
+void buffer_append(Buffer *self, const void *data, size_t size) {
+    buffer_ensure_capacity(self, self->size + size);
+    memcpy((char*)self->data + self->size, data, size);
+    self->size += size;
+}
+
+void* buffer_pop(Buffer *self, size_t size) {
+    assert(self->size >= size);
+    self->size -= size;
+    return (char*)self->data + self->size;
+}
+
+void* buffer_begin(Buffer *self) {
+    return self->data;
+}
+
+void* buffer_end(Buffer *self) {
+    return (char*)self->data + self->size;
+}
diff --git a/buffer.h b/buffer.h
new file mode 100644
index 0000000..a8c1940
--- /dev/null
+++ b/buffer.h
@@ -0,0 +1,30 @@
+#ifndef BUFFER_H
+#define BUFFER_H
+
+#include <stddef.h>
+
+/*
+    TODO: Optimize small size buffers by using data and size members (16 bytes on x86)
+    instead of heap allocation
+*/
+typedef struct {
+    void *data;
+    size_t size;
+    size_t capacity;
+} Buffer;
+
+void buffer_init(Buffer *self);
+void buffer_deinit(Buffer *self);
+
+void buffer_append(Buffer *self, const void *data, size_t size);
+/*
+    This function changes the size of the buffer without changing the capacity
+    and returns the value at the back of the buffer, which is valid until @tsl_buffer_append or
+    @tsl_buffer_deinit is called.
+    The buffer size has to be larger or equal to @size.
+*/
+void* buffer_pop(Buffer *self, size_t size);
+void* buffer_begin(Buffer *self);
+void* buffer_end(Buffer *self);
+
+#endif
diff --git a/build.sh b/build.sh
new file mode 100755
index 0000000..575c08b
--- /dev/null
+++ b/build.sh
@@ -0,0 +1,8 @@
+#!/bin/sh
+
+CFLAGS="-O0 -g3 -Wall -Wextra -Werror"
+#CFLAGS="-O3 -s"
+#LIBS="-lcurl"
+LIBS=""
+#gcc
+musl-gcc -static main.c program.c alloc.c buffer.c -o automedia $CFLAGS $LIBS
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..04c8f29
--- /dev/null
+++ b/main.c
@@ -0,0 +1,60 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "program.h"
+#include "buffer.h"
+
+static int program_buffer_write_callback(char *data, int size, void *userdata) {
+    Buffer *buffer = userdata;
+    buffer_append(buffer, data, size);
+    return 0;
+}
+
+static void usage() {
+    fprintf(stderr, "usage: automedia COMMAND\n");
+    fprintf(stderr, "\n");
+    fprintf(stderr, "COMMANDS\n");
+    fprintf(stderr, "  add           Add media to track\n");
+    fprintf(stderr, "  sync          Start syncing tracked media\n");
+    fprintf(stderr, "  downloaded    List downloaded media\n");
+    exit(1);
+}
+
+static void usage_add() {
+    fprintf(stderr, "usage: automedia add <type> <url|filename> [--name name] [--start-after start_after]\n");
+    fprintf(stderr, "OPTIONS\n");
+    fprintf(stderr, "  type             The type should be either rss or html\n");
+    fprintf(stderr, "  url              The url to the rss or html\n");
+    fprintf(stderr, "  filename         The filename of an episode of an existing serie to start track. Currently only works with rss on https://nyaa.si\n");
+    fprintf(stderr, "  --name           The display name to be used for the media. Optional for rss, in which case the name will be retries from rss TITLE, required for html\n");
+    fprintf(stderr, "  --start-after    The sync should start downloading media after this item. This --start-after value should be the title of the episode/chapter (Optional, default is to start from the first item)\n");
+    fprintf(stderr, "EXAMPLES\n");
+    fprintf(stderr, "  automedia.py add rss 'https://nyaa.si/?page=rss&q=Tejina-senpai+1080p&c=0_0&f=0&u=HorribleSubs'\n");
+    fprintf(stderr, "  automedia.py add html 'https://manganelo.com/manga/read_naruto_manga_online_free3' --name Naruto\n");
+    fprintf(stderr, "  automedia.py add rss '[Erai-raws] Saiki Kusuo no Psi Nan - Kanketsu-hen - 01 [1080p][Multiple Subtitle].mkv'\n");
+    exit(1);
+}
+
+static void usage_sync() {
+    fprintf(stderr, "usage: automedia sync <download_dir>\n");
+    fprintf(stderr, "OPTIONS\n");
+    fprintf(stderr, "  download_dir    The path where media should be downloaded to\n");
+    fprintf(stderr, "EXAMPLES\n");
+    fprintf(stderr, "  automedia.py sync /home/adam/Downloads/automedia\n");
+    exit(1);
+}
+
+int main(int argc, char **argv) {
+    if(argc < 3)
+        usage();
+
+    Buffer buffer;
+    buffer_init(&buffer);
+
+    const char *args[] = { "curl", "-s", "-L", "-f", "https://google.com", NULL };
+    program_exec(args, program_buffer_write_callback, &buffer);
+    printf("program output: %.*s\n", (int)buffer.size, (char*)buffer.data);
+
+    buffer_deinit(&buffer);
+
+    return 0;
+}
diff --git a/program.c b/program.c
new file mode 100644
index 0000000..6004ccb
--- /dev/null
+++ b/program.c
@@ -0,0 +1,102 @@
+#include "program.h"
+#include <unistd.h>
+#include <sys/wait.h>
+#include <sys/prctl.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#define READ_END 0
+#define WRITE_END 1
+
+int program_exec(const char **args, ProgramOutputCallback output_callback, void *userdata) {
+    /* 1 arguments */
+    if(args[0] == NULL)
+        return -1;
+    
+    int fd[2];
+    if(pipe(fd) == -1) {
+        perror("Failed to open pipe");
+        return -2;
+    }
+
+    pid_t parent_pid = getpid();
+
+    pid_t pid = fork();
+    if(pid == -1) {
+        perror("Failed to fork");
+        return -3;
+    } else if(pid == 0) { /* child */
+        if(prctl(PR_SET_PDEATHSIG, SIGTERM) == -1) {
+            perror("prctl(PR_SET_PDEATHSIG, SIGTERM) failed");
+            exit(127);
+        }
+
+        /* Test if the parent died before the above call to prctl */
+        if(getppid() != parent_pid)
+            exit(127);
+
+        dup2(fd[WRITE_END], STDOUT_FILENO);
+        close(fd[READ_END]);
+        close(fd[WRITE_END]);
+
+        execvp(args[0], (char* const*)args);
+        perror("execvp");
+        exit(127);
+    } else { /* parent */
+        close(fd[WRITE_END]);
+
+        int result = 0;
+        int status;
+
+        char buffer[4097];
+
+        for(;;) {
+            ssize_t bytes_read = read(fd[READ_END], buffer, sizeof(buffer) - 1);
+            if(bytes_read == 0) {
+                break;
+            } else if(bytes_read == -1) {
+                int err = errno;
+                fprintf(stderr, "Failed to read from pipe to program %s, error: %s\n", args[0], strerror(err));
+                result = -err;
+                goto cleanup;
+            }
+
+            buffer[bytes_read] = '\0';
+            if(output_callback && output_callback(buffer, bytes_read, userdata) != 0)
+                break;
+        }
+
+        if(waitpid(pid, &status, 0) == -1) {
+            perror("waitpid failed");
+            result = -5;
+            goto cleanup;
+        }
+
+        if(!WIFEXITED(status)) {
+            result = -4;
+            goto cleanup;
+        }
+
+        int exit_status = WEXITSTATUS(status);
+        if(exit_status != 0) {
+            fprintf(stderr, "Failed to execute program (");
+            const char **arg = args;
+            while(*arg) {
+                if(arg != args)
+                    fputc(' ', stderr);
+                fprintf(stderr, "'%s'", *arg);
+                ++arg;
+            }
+            fprintf(stderr, "), exit status %d\n", exit_status);
+            result = -exit_status;
+            goto cleanup;
+        }
+
+        cleanup:
+        close(fd[READ_END]);
+        return result;
+    }
+}
diff --git a/program.h b/program.h
new file mode 100644
index 0000000..4c93066
--- /dev/null
+++ b/program.h
@@ -0,0 +1,13 @@
+#ifndef PROGRAM_H
+#define PROGRAM_H
+
+/* Return 0 if you want to continue reading. @data is null-terminated */
+typedef int (*ProgramOutputCallback)(char *data, int size, void *userdata);
+
+/*
+    @args need to have at least 2 arguments. The first which is the program name
+    and the last which is NULL, which indicates end of args
+*/
+int program_exec(const char **args, ProgramOutputCallback output_callback, void *userdata);
+
+#endif