cell/source/qjs_fd.c

#include "qjs_fd.h"
#include "qjs_blob.h"
#include "jsffi.h"

#include <fcntl.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <dirent.h>
#include <stdlib.h>
#include <errno.h>
#include <stdio.h>

// File descriptor wrapper structure
typedef struct {
    int fd;
} FDWrapper;

// Free function for file descriptor
static void FD_free(JSRuntime *rt, FDWrapper *fdw)
{
    if (fdw->fd >= 0) {
        close(fdw->fd);
    }
    js_free_rt(rt, fdw);
}

// Class definition for file descriptor
static JSClassID js_fd_class_id;

static JSClassDef js_fd_class = {
    "FileDescriptor",
    .finalizer = (JSClassFinalizer *)FD_free,
};

// Helper to convert JS value to FDWrapper
static FDWrapper *js2fd(JSContext *ctx, JSValueConst obj)
{
    FDWrapper *fdw = JS_GetOpaque2(ctx, obj, js_fd_class_id);
    if (!fdw) {
        JS_ThrowTypeError(ctx, "Expected file descriptor object");
        return NULL;
    }
    return fdw;
}

// Helper to create JS FDWrapper object
static JSValue fd2js(JSContext *ctx, int fd)
{
    FDWrapper *fdw = js_mallocz(ctx, sizeof(FDWrapper));
    if (!fdw) return JS_EXCEPTION;
    
    fdw->fd = fd;
    
    JSValue obj = JS_NewObjectClass(ctx, js_fd_class_id);
    if (JS_IsException(obj)) {
        js_free(ctx, fdw);
        return obj;
    }
    
    JS_SetOpaque(obj, fdw);
    return obj;
}

// Helper function for writing
static ssize_t js_fd_write_helper(JSContext *js, int fd, JSValue val)
{
    size_t len;
    ssize_t wrote;
    if (JS_IsString(val)) {
        const char *data = JS_ToCStringLen(js, &len, val);
        wrote = write(fd, data, len);
        JS_FreeCString(js, data);
    } else {
        unsigned char *data = js_get_blob_data(js, &len, val);
        wrote = write(fd, data, len);
    }
    return wrote;
}


// POSIX FILE DESCRIPTOR FUNCTIONS

JSC_SCALL(fd_open,
    int flags = O_RDWR | O_CREAT;
    mode_t mode = 0644;
    
    // Parse optional flags argument
    if (argc > 1 && JS_IsString(argv[1])) {
        const char *flag_str = JS_ToCString(js, argv[1]);
        flags = 0;
        
        if (strchr(flag_str, 'r')) flags |= O_RDONLY;
        if (strchr(flag_str, 'w')) flags |= O_WRONLY | O_CREAT | O_TRUNC;
        if (strchr(flag_str, 'a')) flags |= O_WRONLY | O_CREAT | O_APPEND;
        if (strchr(flag_str, '+')) {
            flags &= ~(O_RDONLY | O_WRONLY);
            flags |= O_RDWR;
        }
        
        JS_FreeCString(js, flag_str);
    }
    
    int fd = open(str, flags, mode);
    if (fd < 0)
        ret = JS_ThrowReferenceError(js, "open failed: %s", strerror(errno));
    else
        ret = fd2js(js, fd);
)

JSC_CCALL(fd_write,
    FDWrapper *fdw = js2fd(js, argv[0]);
    if (!fdw) return JS_EXCEPTION;
    
    ssize_t wrote = js_fd_write_helper(js, fdw->fd, argv[1]);
    if (wrote < 0)
        return JS_ThrowReferenceError(js, "write failed: %s", strerror(errno));
    
    return JS_NewInt64(js, wrote);
)

JSC_CCALL(fd_read,
    FDWrapper *fdw = js2fd(js, argv[0]);
    if (!fdw) return JS_EXCEPTION;
    
    size_t size = 4096;
    if (argc > 1)
        size = js2number(js, argv[1]);
    
    void *buf = malloc(size);
    if (!buf)
        return JS_ThrowReferenceError(js, "malloc failed");
    
    ssize_t bytes_read = read(fdw->fd, buf, size);
    if (bytes_read < 0) {
        free(buf);
        return JS_ThrowReferenceError(js, "read failed: %s", strerror(errno));
    }
    
    ret = js_new_blob_stoned_copy(js, buf, bytes_read);
    free(buf);
    return ret;
)

JSC_CCALL(fd_lseek,
    FDWrapper *fdw = js2fd(js, argv[0]);
    if (!fdw) return JS_EXCEPTION;
    
    off_t offset = js2number(js, argv[1]);
    int whence = SEEK_SET;
    
    if (argc > 2) {
        const char *whence_str = JS_ToCString(js, argv[2]);
        if (strcmp(whence_str, "cur") == 0) whence = SEEK_CUR;
        else if (strcmp(whence_str, "end") == 0) whence = SEEK_END;
        JS_FreeCString(js, whence_str);
    }
    
    off_t new_pos = lseek(fdw->fd, offset, whence);
    if (new_pos < 0)
        return JS_ThrowReferenceError(js, "lseek failed: %s", strerror(errno));
    
    return JS_NewInt64(js, new_pos);
)

JSC_CCALL(fd_getcwd,
    char buf[PATH_MAX];
    if (getcwd(buf, sizeof(buf)) == NULL)
        return JS_ThrowReferenceError(js, "getcwd failed: %s", strerror(errno));
    return JS_NewString(js, buf);
)

JSC_SCALL(fd_rmdir,
    if (rmdir(str) != 0)
        ret = JS_ThrowReferenceError(js, "could not remove directory %s: %s", str, strerror(errno));
)

JSC_SCALL(fd_mkdir,
    if (mkdir(str, 0755) != 0)
        ret = JS_ThrowReferenceError(js, "could not make directory %s: %s", str, strerror(errno));
)

JSC_CCALL(fd_fsync,
    FDWrapper *fdw = js2fd(js, argv[0]);
    if (!fdw) return JS_EXCEPTION;
    
    if (fsync(fdw->fd) != 0)
        return JS_ThrowReferenceError(js, "fsync failed: %s", strerror(errno));
    
    return JS_UNDEFINED;
)

JSC_CCALL(fd_close,
    FDWrapper *fdw = js2fd(js, argv[0]);
    if (!fdw) return JS_EXCEPTION;
    
    if (fdw->fd >= 0) {
        close(fdw->fd);
        fdw->fd = -1;
    }
    
    return JS_UNDEFINED;
)


static const JSCFunctionListEntry js_fd_funcs[] = {
    MIST_FUNC_DEF(fd, open, 2),
    MIST_FUNC_DEF(fd, write, 2),
    MIST_FUNC_DEF(fd, read, 2),
    MIST_FUNC_DEF(fd, lseek, 3),
    MIST_FUNC_DEF(fd, getcwd, 0),
    MIST_FUNC_DEF(fd, rmdir, 1),
    MIST_FUNC_DEF(fd, mkdir, 1),
    MIST_FUNC_DEF(fd, fsync, 1),
    MIST_FUNC_DEF(fd, close, 1),
};

JSValue js_fd_use(JSContext *js) {
    // Initialize the file descriptor class
    JS_NewClassID(&js_fd_class_id);
    JS_NewClass(JS_GetRuntime(js), js_fd_class_id, &js_fd_class);
    
    JSValue proto = JS_NewObject(js);
    JS_SetClassProto(js, js_fd_class_id, proto);
    
    JSValue mod = JS_NewObject(js);
    JS_SetPropertyFunctionList(js, mod, js_fd_funcs, countof(js_fd_funcs));
    return mod;
}