fileio.c

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#include <assert.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <dirent.h>
 
#include <kuroko/vm.h>
#include <kuroko/value.h>
#include <kuroko/object.h>
#include <kuroko/memory.h>
#include <kuroko/util.h>
 
struct File {
    KrkInstance inst;
    FILE * filePtr;
    int unowned;
};
 
#define IS_File(o) (krk_isInstanceOf(o, KRK_BASE_CLASS(File)))
#define AS_File(o) ((struct File*)AS_OBJECT(o))
 
#define IS_BinaryFile(o) (krk_isInstanceOf(o, KRK_BASE_CLASS(BinaryFile)))
#define AS_BinaryFile(o) ((struct File*)AS_OBJECT(o))
 
struct Directory {
    KrkInstance inst;
    DIR * dirPtr;
};
 
#define IS_Directory(o) (krk_isInstanceOf(o, KRK_BASE_CLASS(Directory)))
#define AS_Directory(o) ((struct Directory*)AS_OBJECT(o))
 
#define CURRENT_CTYPE struct File *
#define CURRENT_NAME  self
 
KRK_Function(open) {
    FUNCTION_TAKES_AT_LEAST(1);
    FUNCTION_TAKES_AT_MOST(2);
    CHECK_ARG(0,str,KrkString*,filename);
    if (argc == 2 && !IS_STRING(argv[1])) return TYPE_ERROR(str,argv[1]);
    KrkValue arg;
    int isBinary = 0;
    if (argc == 1) {
        arg = OBJECT_VAL(S("r"));
        krk_push(arg); /* Will be peeked to find arg string for fopen */
    } else {
        /* Check mode against allowable modes */
        if (AS_STRING(argv[1])->length == 0) return krk_runtimeError(vm.exceptions->typeError, "open: mode string must not be empty");
        for (size_t i = 0; i < AS_STRING(argv[1])->length-1; ++i) {
            if (AS_CSTRING(argv[1])[i] == 'b') {
                return krk_runtimeError(vm.exceptions->typeError, "open: 'b' mode indicator must appear at end of mode string");
            }
        }
        arg = argv[1];
        if (AS_CSTRING(argv[1])[AS_STRING(argv[1])->length-1] == 'b') {
            KrkValue tmp = OBJECT_VAL(krk_copyString(AS_CSTRING(argv[1]), AS_STRING(argv[1])->length-1));
            krk_push(tmp);
            isBinary = 1;
        } else {
            krk_push(arg);
        }
    }
 
    FILE * file = fopen(filename->chars, AS_CSTRING(krk_peek(0)));
    if (!file) return krk_runtimeError(vm.exceptions->ioError, "open: failed to open file; system returned: %s", strerror(errno));
 
    /* Now let's build an object to hold it */
    KrkInstance * fileObject = krk_newInstance(isBinary ? KRK_BASE_CLASS(BinaryFile) : KRK_BASE_CLASS(File));
    krk_push(OBJECT_VAL(fileObject));
 
    /* Let's put the filename in there somewhere... */
    krk_attachNamedValue(&fileObject->fields, "filename", OBJECT_VAL(filename));
    krk_attachNamedValue(&fileObject->fields, "modestr", arg);
 
    ((struct File*)fileObject)->filePtr = file;
 
    krk_pop();
    krk_pop();
    return OBJECT_VAL(fileObject);
}
 
#define BLOCK_SIZE 1024
 
KRK_Method(File,__str__) {
    METHOD_TAKES_NONE();
    KrkValue filename;
    KrkValue modestr;
    if (!krk_tableGet(&self->inst.fields, OBJECT_VAL(S("filename")), &filename) || !IS_STRING(filename)) return krk_runtimeError(vm.exceptions->baseException, "Corrupt File");
    if (!krk_tableGet(&self->inst.fields, OBJECT_VAL(S("modestr")), &modestr) || !IS_STRING(modestr)) return krk_runtimeError(vm.exceptions->baseException, "Corrupt File");
 
    return krk_stringFromFormat("<%s file '%S', mode '%S' at %p>", self->filePtr ? "open" : "closed", AS_STRING(filename), AS_STRING(modestr), (void*)self);
}
 
KRK_Method(File,readline) {
    METHOD_TAKES_NONE();
    FILE * file = self->filePtr;
 
    if (!file || feof(file)) {
        return NONE_VAL();
    }
 
    size_t sizeRead = 0;
    size_t spaceAvailable = 0;
    char * buffer = NULL;
 
    do {
        if (spaceAvailable < sizeRead + BLOCK_SIZE) {
            spaceAvailable = (spaceAvailable ? spaceAvailable * 2 : (2 * BLOCK_SIZE));
            buffer = realloc(buffer, spaceAvailable);
        }
 
        char * target = &buffer[sizeRead];
        while (sizeRead < spaceAvailable) {
            int c = fgetc(file);
            if (krk_currentThread.flags & KRK_THREAD_SIGNALLED) break;
            if (c < 0) break;
            sizeRead++;
            *target++ = c;
            if (c == '\n') goto _finish_line;
        }
 
        if (krk_currentThread.flags & KRK_THREAD_SIGNALLED) break;
    } while (!feof(file));
 
_finish_line: (void)0;
    if (sizeRead == 0) {
        free(buffer);
        return NONE_VAL();
    }
 
    /* Make a new string to fit our output. */
    KrkString * out = krk_copyString(buffer,sizeRead);
    free(buffer);
    return OBJECT_VAL(out);
}
 
KRK_Method(File,readlines) {
    METHOD_TAKES_NONE();
    KrkValue myList = krk_list_of(0,NULL,0);
    krk_push(myList);
 
    for (;;) {
        KrkValue line = FUNC_NAME(File,readline)(1, argv, 0);
        if (IS_NONE(line)) break;
        if (krk_currentThread.flags & KRK_THREAD_SIGNALLED) break;
 
        krk_push(line);
        krk_writeValueArray(AS_LIST(myList), line);
        krk_pop(); /* line */
    }
 
    krk_pop(); /* myList */
    return myList;
}
 
KRK_Method(File,read) {
    METHOD_TAKES_AT_MOST(1);
 
    krk_integer_type sizeToRead = -1;
    if (argc > 1) {
        CHECK_ARG(1,int,krk_integer_type,sizeFromArg);
        if (sizeFromArg < -1) return krk_runtimeError(vm.exceptions->valueError, "size must be >= -1");
        sizeToRead = sizeFromArg;
    }
 
    /* Get the file ptr reference */
    FILE * file = self->filePtr;
 
    if (!file || feof(file)) {
        return NONE_VAL();
    }
 
    /* We'll do our read entirely with some native buffers and manage them here. */
    size_t sizeRead = 0;
    size_t spaceAvailable = 0;
    char * buffer = NULL;
 
    if (sizeToRead == -1) {
        do {
            if (spaceAvailable < sizeRead + BLOCK_SIZE) {
                spaceAvailable = (spaceAvailable ? spaceAvailable * 2 : (2 * BLOCK_SIZE));
                buffer = realloc(buffer, spaceAvailable);
            }
 
            char * target = &buffer[sizeRead];
            size_t newlyRead = fread(target, 1, BLOCK_SIZE, file);
            if (krk_currentThread.flags & KRK_THREAD_SIGNALLED) break;
 
            if (newlyRead < BLOCK_SIZE) {
                if (ferror(file)) {
                    free(buffer);
                    return krk_runtimeError(vm.exceptions->ioError, "Read error.");
                }
            }
 
            sizeRead += newlyRead;
        } while (!feof(file));
    } else {
        spaceAvailable = sizeToRead;
        buffer = realloc(buffer, spaceAvailable);
        sizeRead = fread(buffer, 1, sizeToRead, file);
    }
 
    /* Make a new string to fit our output. */
    KrkString * out = krk_copyString(buffer,sizeRead);
    free(buffer);
    return OBJECT_VAL(out);
}
 
KRK_Method(File,write) {
    METHOD_TAKES_EXACTLY(1);
    if (!IS_STRING(argv[1])) return TYPE_ERROR(str,argv[1]);
    /* Find the file ptr reference */
    FILE * file = self->filePtr;
 
    if (!file || feof(file)) {
        return NONE_VAL();
    }
 
    return INTEGER_VAL(fwrite(AS_CSTRING(argv[1]), 1, AS_STRING(argv[1])->length, file));
}
 
KRK_Method(File,close) {
    METHOD_TAKES_NONE();
    FILE * file = self->filePtr;
    if (file) fclose(file);
    self->filePtr = NULL;
    return NONE_VAL();
}
 
KRK_Method(File,flush) {
    METHOD_TAKES_NONE();
    FILE * file = self->filePtr;
    if (file) fflush(file);
    return NONE_VAL();
}
 
KRK_Method(File,__init__) {
    return krk_runtimeError(vm.exceptions->typeError, "File objects can not be instantiated; use fileio.open() to obtain File objects.");
}
 
KRK_Method(File,__enter__) {
    return NONE_VAL();
}
KRK_Method(File,__exit__) {
    return FUNC_NAME(File,close)(1,argv,0);
}
 
static void makeFileInstance(KrkInstance * module, const char name[], FILE * file, const char mode[]) {
    KrkInstance * fileObject = krk_newInstance(KRK_BASE_CLASS(File));
    krk_push(OBJECT_VAL(fileObject));
    KrkValue filename = OBJECT_VAL(krk_copyString(name,strlen(name)));
    krk_push(filename);
    KrkValue modestr = OBJECT_VAL(krk_copyString(mode,strlen(mode)));
    krk_push(modestr);
 
    krk_attachNamedValue(&fileObject->fields, "filename", filename);
    krk_attachNamedValue(&fileObject->fields, "modestr", modestr);
    ((struct File*)fileObject)->filePtr = file;
    ((struct File*)fileObject)->unowned = 1;
 
    krk_attachNamedObject(&module->fields, name, (KrkObj*)fileObject);
 
    krk_pop(); /* modestr */
    krk_pop(); /* filename */
    krk_pop(); /* fileObject */
}
 
KRK_Method(BinaryFile,readline) {
    METHOD_TAKES_NONE();
    FILE * file = self->filePtr;
 
    if (!file || feof(file)) {
        return NONE_VAL();
    }
 
    size_t sizeRead = 0;
    size_t spaceAvailable = 0;
    char * buffer = NULL;
 
    do {
        if (spaceAvailable < sizeRead + BLOCK_SIZE) {
            spaceAvailable = (spaceAvailable ? spaceAvailable * 2 : (2 * BLOCK_SIZE));
            buffer = realloc(buffer, spaceAvailable);
        }
 
        char * target = &buffer[sizeRead];
        while (sizeRead < spaceAvailable) {
            int c = fgetc(file);
            if (krk_currentThread.flags & KRK_THREAD_SIGNALLED) break;
            if (c < 0) break;
            sizeRead++;
            *target++ = c;
            if (c == '\n') goto _finish_line;
        }
 
        if (krk_currentThread.flags & KRK_THREAD_SIGNALLED) break;
    } while (!feof(file));
 
_finish_line: (void)0;
    if (sizeRead == 0) {
        free(buffer);
        return NONE_VAL();
    }
 
    /* Make a new string to fit our output. */
    KrkBytes * out = krk_newBytes(sizeRead, (unsigned char*)buffer);
    free(buffer);
    return OBJECT_VAL(out);
}
 
KRK_Method(BinaryFile,readlines) {
    METHOD_TAKES_NONE();
    KrkValue myList = krk_list_of(0,NULL,0);
    krk_push(myList);
 
    for (;;) {
        KrkValue line = FUNC_NAME(BinaryFile,readline)(1, argv, 0);
        if (IS_NONE(line)) break;
        if (krk_currentThread.flags & KRK_THREAD_SIGNALLED) break;
 
        krk_push(line);
        krk_writeValueArray(AS_LIST(myList), line);
        krk_pop(); /* line */
    }
 
    krk_pop(); /* myList */
    return myList;
}
 
KRK_Method(BinaryFile,read) {
    METHOD_TAKES_AT_MOST(1);
 
    krk_integer_type sizeToRead = -1;
    if (argc > 1) {
        CHECK_ARG(1,int,krk_integer_type,sizeFromArg);
        if (sizeFromArg < -1) return krk_runtimeError(vm.exceptions->valueError, "size must be >= -1");
        sizeToRead = sizeFromArg;
    }
 
    /* Get the file ptr reference */
    FILE * file = self->filePtr;
 
    if (!file || feof(file)) {
        return NONE_VAL();
    }
 
    /* We'll do our read entirely with some native buffers and manage them here. */
    size_t sizeRead = 0;
    size_t spaceAvailable = 0;
    char * buffer = NULL;
 
    if (sizeToRead == -1) {
        do {
            if (spaceAvailable < sizeRead + BLOCK_SIZE) {
                spaceAvailable = (spaceAvailable ? spaceAvailable * 2 : (2 * BLOCK_SIZE));
                buffer = realloc(buffer, spaceAvailable);
            }
 
            char * target = &buffer[sizeRead];
            size_t newlyRead = fread(target, 1, BLOCK_SIZE, file);
 
            if (krk_currentThread.flags & KRK_THREAD_SIGNALLED) break;
 
            if (newlyRead < BLOCK_SIZE) {
                if (ferror(file)) {
                    free(buffer);
                    return krk_runtimeError(vm.exceptions->ioError, "Read error.");
                }
            }
 
            sizeRead += newlyRead;
        } while (!feof(file));
    } else {
        spaceAvailable = sizeToRead;
        buffer = realloc(buffer, spaceAvailable);
        sizeRead = fread(buffer, 1, sizeToRead, file);
    }
 
    /* Make a new string to fit our output. */
    KrkBytes * out = krk_newBytes(sizeRead, (unsigned char*)buffer);
    free(buffer);
    return OBJECT_VAL(out);
}
 
KRK_Method(BinaryFile,write) {
    METHOD_TAKES_EXACTLY(1);
    if (!IS_BYTES(argv[1])) return TYPE_ERROR(bytes,argv[1]);
    /* Find the file ptr reference */
    FILE * file = self->filePtr;
 
    if (!file || feof(file)) {
        return NONE_VAL();
    }
 
    return INTEGER_VAL(fwrite(AS_BYTES(argv[1])->bytes, 1, AS_BYTES(argv[1])->length, file));
}
 
#undef CURRENT_CTYPE
 
static void _file_sweep(KrkInstance * self) {
    struct File * me = (void *)self;
    if (me->filePtr && !me->unowned) {
        fclose(me->filePtr);
        me->filePtr = NULL;
    }
}
 
static void _dir_sweep(KrkInstance * self) {
    struct Directory * me = (void *)self;
    if (me->dirPtr) {
        closedir(me->dirPtr);
        me->dirPtr = NULL;
    }
}
 
KRK_Function(opendir) {
    FUNCTION_TAKES_EXACTLY(1);
    CHECK_ARG(0,str,KrkString*,path);
 
    DIR * dir = opendir(path->chars);
    if (!dir) return krk_runtimeError(vm.exceptions->ioError, "opendir: %s", strerror(errno));
 
    struct Directory * dirObj = (void *)krk_newInstance(KRK_BASE_CLASS(Directory));
    krk_push(OBJECT_VAL(dirObj));
 
    krk_attachNamedValue(&dirObj->inst.fields, "path", OBJECT_VAL(path));
    dirObj->dirPtr = dir;
 
    return krk_pop();
}
 
#define CURRENT_CTYPE struct Directory *
 
KRK_Method(Directory,__call__) {
    METHOD_TAKES_NONE();
    if (!self->dirPtr) return argv[0];
    struct dirent * entry = readdir(self->dirPtr);
    if (!entry) return argv[0];
 
    KrkValue outDict = krk_dict_of(0, NULL, 0);
    krk_push(outDict);
 
    krk_attachNamedValue(AS_DICT(outDict), "name", OBJECT_VAL(krk_copyString(entry->d_name,strlen(entry->d_name))));
    krk_attachNamedValue(AS_DICT(outDict), "inode", INTEGER_VAL(entry->d_ino));
 
    return krk_pop();
}
 
KRK_Method(Directory,__iter__) {
    METHOD_TAKES_NONE();
    return argv[0];
}
 
KRK_Method(Directory,close) {
    METHOD_TAKES_NONE();
    if (self->dirPtr) {
        closedir(self->dirPtr);
        self->dirPtr = NULL;
    }
    return NONE_VAL();
}
 
KRK_Method(Directory,__repr__) {
    METHOD_TAKES_NONE();
    KrkValue path;
    if (!krk_tableGet(&self->inst.fields, OBJECT_VAL(S("path")), &path) || !IS_STRING(path))
        return krk_runtimeError(vm.exceptions->valueError, "corrupt Directory");
 
    return krk_stringFromFormat("<%s directory '%S' at %p>", self->dirPtr ? "open" : "closed", AS_STRING(path), (void*)self);
}
 
KRK_Method(Directory,__enter__) {
    return NONE_VAL();
}
KRK_Method(Directory,__exit__) {
    return FUNC_NAME(Directory,close)(1,argv,0);
}
 
void krk_module_init_fileio(void) {
    KrkInstance * module = krk_newInstance(vm.baseClasses->moduleClass);
    krk_attachNamedObject(&vm.modules, "fileio", (KrkObj*)module);
    krk_attachNamedObject(&module->fields, "__name__", (KrkObj*)S("fileio"));
    krk_attachNamedValue(&module->fields, "__file__", NONE_VAL());
    KRK_DOC(module,
        "@brief Provides access to C <stdio> buffered file I/O functions.\n\n"
        "The @c fileio module provides classes and functions for reading "
        "and writing files using the system's buffer I/O interfaces, as "
        "well as classes for listing the contents of directories."
    );
 
    /* Define a class to represent files. (Should this be a helper method?) */
    KrkClass * File = krk_makeClass(module, &KRK_BASE_CLASS(File), "File", KRK_BASE_CLASS(object));
    KRK_DOC(File,"Interface to a buffered file stream.");
    File->allocSize = sizeof(struct File);
    File->_ongcsweep = _file_sweep;
 
    /* Add methods to it... */
    KRK_DOC(BIND_METHOD(File,read), "@brief Read from the stream.\n"
        "@arguments bytes=-1\n\n"
        "Reads up to @p bytes bytes from the stream. If @p bytes is @c -1 then reading "
        "will continue until the system returns _end of file_.");
    KRK_DOC(BIND_METHOD(File,readline), "@brief Read one line from the stream.");
    KRK_DOC(BIND_METHOD(File,readlines), "@brief Read the entire stream and return a list of lines.");
    KRK_DOC(BIND_METHOD(File,write), "@brief Write to the stream.\n"
        "@arguments data\n\n"
        "Writes the contents of @p data to the stream.");
    KRK_DOC(BIND_METHOD(File,close), "@brief Close the stream and flush any remaining buffered writes.");
    KRK_DOC(BIND_METHOD(File,flush), "@brief Flush unbuffered writes to the stream.");
    BIND_METHOD(File,__str__);
    KRK_DOC(BIND_METHOD(File,__init__), "@bsnote{%File objects can not be initialized using this constructor. "
        "Use the <a class=\"el\" href=\"#open\">open()</a> function instead.}");
    BIND_METHOD(File,__enter__);
    BIND_METHOD(File,__exit__);
    krk_defineNative(&File->methods, "__repr__", FUNC_NAME(File,__str__));
    krk_finalizeClass(File);
 
    KrkClass * BinaryFile = krk_makeClass(module, &KRK_BASE_CLASS(BinaryFile), "BinaryFile", File);
    KRK_DOC(BinaryFile,
        "Equivalent to @ref File but using @ref bytes instead of string @ref str."
    );
    BIND_METHOD(BinaryFile,read);
    BIND_METHOD(BinaryFile,readline);
    BIND_METHOD(BinaryFile,readlines);
    BIND_METHOD(BinaryFile,write);
    krk_finalizeClass(BinaryFile);
 
    KrkClass * Directory = krk_makeClass(module, &KRK_BASE_CLASS(Directory), "Directory", KRK_BASE_CLASS(object));
    KRK_DOC(Directory,
        "Represents an opened file system directory."
    );
    Directory->allocSize = sizeof(struct Directory);
    Directory->_ongcsweep = _dir_sweep;
    BIND_METHOD(Directory,__repr__);
    KRK_DOC(BIND_METHOD(Directory,__iter__), "@brief Iterates over the contents of the directory.\n\n"
        "Each iteration returns @ref dict with two entries: <i>\"name\"</i> and <i>\"inode\"</i>.");
    KRK_DOC(BIND_METHOD(Directory,__call__), "@brief Yields one iteration through the directory.");
    BIND_METHOD(Directory,__enter__);
    KRK_DOC(BIND_METHOD(Directory,__exit__), "@brief Closes the directory upon exit from a @c with block.");
    KRK_DOC(BIND_METHOD(Directory,close), "@brief Close the directory.\n\nFurther reads can not be made after the directory has been closed.");
    krk_finalizeClass(Directory);
 
    /* Make an instance for stdout, stderr, and stdin */
    makeFileInstance(module, "stdin", stdin, "r");
    makeFileInstance(module, "stdout", stdout, "w");
    makeFileInstance(module, "stderr", stderr, "w");
 
    /* Our base will be the open method */
    KRK_DOC(BIND_FUNC(module,open), "@brief Open a file.\n"
        "@arguments path,mode=\"r\"\n\n"
        "Opens @p path using the modestring @p mode. Supported modestring characters depend on the system implementation. "
        "If the last character of @p mode is @c 'b' a @ref BinaryFile will be returned. If the file could not be opened, "
        "an @ref IOError will be raised.");
    KRK_DOC(BIND_FUNC(module,opendir), "@brief Open a directory for scanning.\n"
        "@arguments path\n\n"
        "Opens the directory at @p path and returns a @ref Directory object. If @p path could not be opened or is not "
        "a directory, @ref IOError will be raised.");
}