Diff: drivers/LocalFileSystem.cpp

Revision:

149:156823d33999

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/drivers/LocalFileSystem.cpp	Fri Oct 28 11:17:30 2016 +0100
@@ -0,0 +1,275 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "drivers/LocalFileSystem.h"
+
+#if DEVICE_LOCALFILESYSTEM
+
+#include "platform/semihost_api.h"
+#include <string.h>
+#include <stdio.h>
+
+namespace mbed {
+
+/* Extension to FINFO type defined in RTL.h (in Keil RL) - adds 'create time'. */
+typedef struct {
+    unsigned char  hr;   /* Hours    [0..23]                  */
+    unsigned char  min;  /* Minutes  [0..59]                  */
+    unsigned char  sec;  /* Seconds  [0..59]                  */
+    unsigned char  day;  /* Day      [1..31]                  */
+    unsigned char  mon;  /* Month    [1..12]                  */
+    unsigned short year; /* Year     [1980..2107]             */
+} FTIME;
+
+typedef struct {         /* File Search info record           */
+    char  name[32];      /* File name                         */
+    long  size;          /* File size in bytes                */
+    int   fileID;        /* System File Identification        */
+    FTIME create_time;   /* Date & time file was created      */
+    FTIME write_time;    /* Date & time of last write         */
+} XFINFO;
+
+#define RESERVED_FOR_USER_APPLICATIONS (0x100) /* 0x100 - 0x1ff */
+#define USR_XFFIND (RESERVED_FOR_USER_APPLICATIONS + 0)
+
+static int xffind (const char *pattern, XFINFO *info) {
+    unsigned param[4];
+
+    param[0] = (unsigned long)pattern;
+    param[1] = (unsigned long)strlen(pattern);
+    param[2] = (unsigned long)info;
+    param[3] = (unsigned long)sizeof(XFINFO);
+
+    return __semihost(USR_XFFIND, param);
+}
+
+#define OPEN_R          0
+#define OPEN_B          1
+#define OPEN_PLUS       2
+#define OPEN_W          4
+#define OPEN_A          8
+#define OPEN_INVALID   -1
+
+int posix_to_semihost_open_flags(int flags) {
+    /* POSIX flags -> semihosting open mode */
+    int openmode;
+    if (flags & O_RDWR) {
+        /* a plus mode */
+        openmode = OPEN_PLUS;
+        if (flags & O_APPEND) {
+            openmode |= OPEN_A;
+        } else if (flags & O_TRUNC) {
+            openmode |= OPEN_W;
+        } else {
+            openmode |= OPEN_R;
+        }
+    } else if (flags & O_WRONLY) {
+        /* write or append */
+        if (flags & O_APPEND) {
+            openmode = OPEN_A;
+        } else {
+            openmode = OPEN_W;
+        }
+    } else if (flags == O_RDONLY) {
+        /* read mode */
+        openmode = OPEN_R;
+    } else {
+        /* invalid flags */
+        openmode = OPEN_INVALID;
+    }
+
+    return openmode;
+}
+
+FILEHANDLE local_file_open(const char* name, int flags) {
+    int openmode = posix_to_semihost_open_flags(flags);
+    if (openmode == OPEN_INVALID) {
+        return (FILEHANDLE)NULL;
+    }
+
+    FILEHANDLE fh = semihost_open(name, openmode);
+    if (fh == -1) {
+        return (FILEHANDLE)NULL;
+    }
+
+    return fh;
+}
+
+LocalFileHandle::LocalFileHandle(FILEHANDLE fh) : _fh(fh), pos(0) {
+    // No lock needed in constructor
+}
+
+int LocalFileHandle::close() {
+    int retval = semihost_close(_fh);
+    delete this;
+    return retval;
+}
+
+ssize_t LocalFileHandle::write(const void *buffer, size_t length) {
+    lock();
+    ssize_t n = semihost_write(_fh, (const unsigned char*)buffer, length, 0); // number of characters not written
+    n = length - n; // number of characters written
+    pos += n;
+    unlock();
+    return n;
+}
+
+ssize_t LocalFileHandle::read(void *buffer, size_t length) {
+    lock();
+    ssize_t n = semihost_read(_fh, (unsigned char*)buffer, length, 0); // number of characters not read
+    n = length - n; // number of characters read
+    pos += n;
+    unlock();
+    return n;
+}
+
+int LocalFileHandle::isatty() {
+    lock();
+    int ret = semihost_istty(_fh);
+    unlock();
+    return ret;
+}
+
+off_t LocalFileHandle::lseek(off_t position, int whence) {
+    lock();
+    if (whence == SEEK_CUR) {
+        position += pos;
+    } else if (whence == SEEK_END) {
+        position += semihost_flen(_fh);
+    } /* otherwise SEEK_SET, so position is fine */
+
+    /* Always seems to return -1, so just ignore for now. */
+    semihost_seek(_fh, position);
+    pos = position;
+    unlock();
+    return position;
+}
+
+int LocalFileHandle::fsync() {
+    lock();
+    int ret = semihost_ensure(_fh);
+    unlock();
+    return ret;
+}
+
+off_t LocalFileHandle::flen() {
+    lock();
+    off_t off = semihost_flen(_fh);
+    unlock();
+    return off;
+}
+
+void LocalFileHandle::lock() {
+    _mutex.lock();
+}
+
+void LocalFileHandle::unlock() {
+    _mutex.unlock();
+}
+
+class LocalDirHandle : public DirHandle {
+
+public:
+    struct dirent cur_entry;
+    XFINFO info;
+
+    LocalDirHandle() : cur_entry(), info() {
+    }
+
+    virtual int closedir() {
+        // No lock can be used in destructor
+        delete this;
+        return 0;
+    }
+
+    virtual struct dirent *readdir() {
+        lock();
+        if (xffind("*", &info)!=0) {
+            unlock();
+            return NULL;
+        }
+        memcpy(cur_entry.d_name, info.name, sizeof(info.name));
+        unlock();
+        return &cur_entry;
+    }
+
+    virtual void rewinddir() {
+        lock();
+        info.fileID = 0;
+        unlock();
+    }
+
+    virtual off_t telldir() {
+        lock();
+        int fileId = info.fileID;
+        unlock();
+        return fileId;
+    }
+
+    virtual void seekdir(off_t offset) {
+        lock();
+        info.fileID = offset;
+        unlock();
+    }
+
+protected:
+    PlatformMutex _mutex;
+
+    virtual void lock() {
+        _mutex.lock();
+    }
+
+    virtual void unlock() {
+        _mutex.unlock();
+    }
+};
+
+FileHandle *LocalFileSystem::open(const char* name, int flags) {
+    // No global state modified so function is thread safe
+
+    /* reject filenames with / in them */
+    for (const char *tmp = name; *tmp; tmp++) {
+        if (*tmp == '/') {
+            return NULL;
+        }
+    }
+
+    int openmode = posix_to_semihost_open_flags(flags);
+    if (openmode == OPEN_INVALID) {
+        return NULL;
+    }
+
+    FILEHANDLE fh = semihost_open(name, openmode);
+    if (fh == -1) {
+        return NULL;
+    }
+    return new LocalFileHandle(fh);
+}
+
+int LocalFileSystem::remove(const char *filename) {
+    // No global state modified so function is thread safe
+
+    return semihost_remove(filename);
+}
+
+DirHandle *LocalFileSystem::opendir(const char *name) {
+    // No global state modified so function is thread safe
+
+    return new LocalDirHandle();
+}
+
+} // namespace mbed
+
+#endif