vdr/tools.h

/*
 * tools.h: Various tools
 *
 * See the main source file 'vdr.c' for copyright information and
 * how to reach the author.
 *
 * $Id: tools.h 2.4 2009/12/23 15:14:39 kls Exp $
 */

#ifndef __TOOLS_H
#define __TOOLS_H

#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <float.h>
#include <iconv.h>
#include <math.h>
#include <poll.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <sys/stat.h>
#include <sys/types.h>

typedef unsigned char uchar;

extern int SysLogLevel;

#define esyslog(a...) void( (SysLogLevel > 0) ? syslog_with_tid(LOG_ERR, a) : void() )
#define isyslog(a...) void( (SysLogLevel > 1) ? syslog_with_tid(LOG_ERR, a) : void() )
#define dsyslog(a...) void( (SysLogLevel > 2) ? syslog_with_tid(LOG_ERR, a) : void() )

#define LOG_ERROR         esyslog("ERROR (%s,%d): %m", __FILE__, __LINE__)
#define LOG_ERROR_STR(s)  esyslog("ERROR: %s: %m", s)

#define SECSINDAY  86400

#define KILOBYTE(n) ((n) * 1024)
#define MEGABYTE(n) ((n) * 1024LL * 1024LL)

#define MALLOC(type, size)  (type *)malloc(sizeof(type) * (size))

#define DELETENULL(p) (delete (p), p = NULL)

#define CHECK(s) { if ((s) < 0) LOG_ERROR; } // used for 'ioctl()' calls
#define FATALERRNO (errno && errno != EAGAIN && errno != EINTR)

#ifndef __STL_CONFIG_H // in case some plugin needs to use the STL
template<class T> inline T min(T a, T b) { return a <= b ? a : b; }
template<class T> inline T max(T a, T b) { return a >= b ? a : b; }
template<class T> inline int sgn(T a) { return a < 0 ? -1 : a > 0 ? 1 : 0; }
template<class T> inline void swap(T &a, T &b) { T t = a; a = b; b = t; }
#endif

void syslog_with_tid(int priority, const char *format, ...) __attribute__ ((format (printf, 2, 3)));

#define BCDCHARTOINT(x) (10 * ((x & 0xF0) >> 4) + (x & 0xF))
int BCD2INT(int x);

// Unfortunately there are no platform independent macros for unaligned
// access, so we do it this way:

template<class T> inline T get_unaligned(T *p)
{
  struct s { T v; } __attribute__((packed));
  return ((s *)p)->v;
}

template<class T> inline void put_unaligned(unsigned int v, T* p)
{
  struct s { T v; } __attribute__((packed));
  ((s *)p)->v = v;
}

// Comparing doubles for equality is unsafe, but unfortunately we can't
// overwrite operator==(double, double), so this will have to do:

inline bool DoubleEqual(double a, double b)
{
  return fabs(a - b) <= DBL_EPSILON;
}

// When handling strings that might contain UTF-8 characters, it may be necessary
// to process a "symbol" that consists of several actual character bytes. The
// following functions allow transparently accessing a "char *" string without
// having to worry about what character set is actually used.

int Utf8CharLen(const char *s);
    ///< Returns the number of character bytes at the beginning of the given
    ///< string that form a UTF-8 symbol.
uint Utf8CharGet(const char *s, int Length = 0);
    ///< Returns the UTF-8 symbol at the beginning of the given string.
    ///< Length can be given from a previous call to Utf8CharLen() to avoid calculating
    ///< it again. If no Length is given, Utf8CharLen() will be called.
int Utf8CharSet(uint c, char *s = NULL);
    ///< Converts the given UTF-8 symbol to a sequence of character bytes and copies
    ///< them to the given string. Returns the number of bytes written. If no string
    ///< is given, only the number of bytes is returned and nothing is copied.
int Utf8SymChars(const char *s, int Symbols);
    ///< Returns the number of character bytes at the beginning of the given
    ///< string that form at most the given number of UTF-8 symbols.
int Utf8StrLen(const char *s);
    ///< Returns the number of UTF-8 symbols formed by the given string of
    ///< character bytes.
char *Utf8Strn0Cpy(char *Dest, const char *Src, int n);
    ///< Copies at most n character bytes from Src to Dst, making sure that the
    ///< resulting copy ends with a complete UTF-8 symbol. The copy is guaranteed
    ///< to be zero terminated.
    ///< Returns a pointer to Dest.
int Utf8ToArray(const char *s, uint *a, int Size);
    ///< Converts the given character bytes (including the terminating 0) into an
    ///< array of UTF-8 symbols of the given Size. Returns the number of symbols
    ///< in the array (without the terminating 0).
int Utf8FromArray(const uint *a, char *s, int Size, int Max = -1);
    ///< Converts the given array of UTF-8 symbols (including the terminating 0)
    ///< into a sequence of character bytes of at most Size length. Returns the
    ///< number of character bytes written (without the terminating 0).
    ///< If Max is given, only that many symbols will be converted.
    ///< The resulting string is always zero-terminated if Size is big enough.

// When allocating buffer space, make sure we reserve enough space to hold
// a string in UTF-8 representation:

#define Utf8BufSize(s) ((s) * 4)

// The following macros automatically use the correct versions of the character
// class functions:

#define Utf8to(conv, c) (cCharSetConv::SystemCharacterTable() ? to##conv(c) : tow##conv(c))
#define Utf8is(ccls, c) (cCharSetConv::SystemCharacterTable() ? is##ccls(c) : isw##ccls(c))

class cCharSetConv {
private:
  iconv_t cd;
  char *result;
  size_t length;
  static char *systemCharacterTable;
public:
  cCharSetConv(const char *FromCode = NULL, const char *ToCode = NULL);
     ///< Sets up a character set converter to convert from FromCode to ToCode.
     ///< If FromCode is NULL, the previously set systemCharacterTable is used
     ///< (or "UTF-8" if no systemCharacterTable has been set).
     ///< If ToCode is NULL, "UTF-8" is used.
  ~cCharSetConv();
  const char *Convert(const char *From, char *To = NULL, size_t ToLength = 0);
     ///< Converts the given Text from FromCode to ToCode (as set in the constructor).
     ///< If To is given, it is used to copy at most ToLength bytes of the result
     ///< (including the terminating 0) into that buffer. If To is not given,
     ///< the result is copied into a dynamically allocated buffer and is valid as
     ///< long as this object lives, or until the next call to Convert(). The
     ///< return value always points to the result if the conversion was successful
     ///< (even if a fixed size To buffer was given and the result didn't fit into
     ///< it). If the string could not be converted, the result points to the
     ///< original From string.
  static const char *SystemCharacterTable(void) { return systemCharacterTable; }
  static void SetSystemCharacterTable(const char *CharacterTable);
  };

class cString {
private:
  char *s;
public:
  cString(const char *S = NULL, bool TakePointer = false);
  cString(const cString &String);
  virtual ~cString();
  operator const void * () const { return s; } // to catch cases where operator*() should be used
  operator const char * () const { return s; } // for use in (const char *) context
  const char * operator*() const { return s; } // for use in (const void *) context (printf() etc.)
  cString &operator=(const cString &String);
  cString &Truncate(int Index); ///< Truncate the string at the given Index (if Index is < 0 it is counted from the end of the string).
  static cString sprintf(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
  static cString sprintf(const char *fmt, va_list &ap);
  };

ssize_t safe_read(int filedes, void *buffer, size_t size);
ssize_t safe_write(int filedes, const void *buffer, size_t size);
void writechar(int filedes, char c);
int WriteAllOrNothing(int fd, const uchar *Data, int Length, int TimeoutMs = 0, int RetryMs = 0);
    ///< Writes either all Data to the given file descriptor, or nothing at all.
    ///< If TimeoutMs is greater than 0, it will only retry for that long, otherwise
    ///< it will retry forever. RetryMs defines the time between two retries.
char *strcpyrealloc(char *dest, const char *src);
char *strn0cpy(char *dest, const char *src, size_t n);
char *strreplace(char *s, char c1, char c2);
char *strreplace(char *s, const char *s1, const char *s2); ///< re-allocates 's' and deletes the original string if necessary!
inline char *skipspace(const char *s)
{
  if ((uchar)*s > ' ') // most strings don't have any leading space, so handle this case as fast as possible
     return (char *)s;
  while (*s && (uchar)*s <= ' ') // avoiding isspace() here, because it is much slower
        s++;
  return (char *)s;
}
char *stripspace(char *s);
char *compactspace(char *s);
cString strescape(const char *s, const char *chars);
bool startswith(const char *s, const char *p);
bool endswith(const char *s, const char *p);
bool isempty(const char *s);
int numdigits(int n);
bool isnumber(const char *s);
cString itoa(int n);
cString AddDirectory(const char *DirName, const char *FileName);
bool EntriesOnSameFileSystem(const char *File1, const char *File2);
int FreeDiskSpaceMB(const char *Directory, int *UsedMB = NULL);
bool DirectoryOk(const char *DirName, bool LogErrors = false);
bool MakeDirs(const char *FileName, bool IsDirectory = false);
bool RemoveFileOrDir(const char *FileName, bool FollowSymlinks = false);
bool RemoveEmptyDirectories(const char *DirName, bool RemoveThis = false);
int DirSizeMB(const char *DirName); ///< returns the total size of the files in the given directory, or -1 in case of an error
char *ReadLink(const char *FileName); ///< returns a new string allocated on the heap, which the caller must delete (or NULL in case of an error)
bool SpinUpDisk(const char *FileName);
void TouchFile(const char *FileName);
time_t LastModifiedTime(const char *FileName);
cString WeekDayName(int WeekDay);
cString WeekDayName(time_t t);
cString WeekDayNameFull(int WeekDay);
cString WeekDayNameFull(time_t t);
cString DayDateTime(time_t t = 0);
cString TimeToString(time_t t);
cString DateString(time_t t);
cString TimeString(time_t t);
uchar *RgbToJpeg(uchar *Mem, int Width, int Height, int &Size, int Quality = 100);
    ///< Converts the given Memory to a JPEG image and returns a pointer
    ///< to the resulting image. Mem must point to a data block of exactly
    ///< (Width * Height) triplets of RGB image data bytes. Upon return, Size
    ///< will hold the number of bytes of the resulting JPEG data.
    ///< Quality can be in the range 0..100 and controls the quality of the
    ///< resulting image, where 100 is "best". The caller takes ownership of
    ///< the result and has to delete it once it is no longer needed.
    ///< The result may be NULL in case of an error.

class cBase64Encoder {
private:
  const uchar *data;
  int length;
  int maxResult;
  int i;
  char *result;
  static const char *b64;
public:
  cBase64Encoder(const uchar *Data, int Length, int MaxResult = 64);
      ///< Sets up a new base 64 encoder for the given Data, with the given Length.
      ///< Data will not be copied and must be valid as long as NextLine() will be
      ///< called. MaxResult defines the maximum number of characters in any
      ///< result line. The resulting lines may be shorter than MaxResult in case
      ///< its value is not a multiple of 4.
  ~cBase64Encoder();
  const char *NextLine(void);
      ///< Returns the next line of encoded data (terminated by '\0'), or NULL if
      ///< there is no more encoded data. The caller must call NextLine() and process
      ///< each returned line until NULL is returned, in order to get the entire
      ///< data encoded. The returned data is only valid until the next time NextLine()
      ///< is called, or until the object is destroyed.
  };

class cTimeMs {
private:
  uint64_t begin;
public:
  cTimeMs(int Ms = 0);
      ///< Creates a timer with ms resolution and an initial timeout of Ms.
  static uint64_t Now(void);
  void Set(int Ms = 0);
  bool TimedOut(void);
  uint64_t Elapsed(void);
  };

class cReadLine {
private:
  size_t size;
  char *buffer;
public:
  cReadLine(void);
  ~cReadLine();
  char *Read(FILE *f);
  };

class cPoller {
private:
  enum { MaxPollFiles = 16 };
  pollfd pfd[MaxPollFiles];
  int numFileHandles;
public:
  cPoller(int FileHandle = -1, bool Out = false);
  bool Add(int FileHandle, bool Out);
  bool Poll(int TimeoutMs = 0);
  };

class cReadDir {
private:
  DIR *directory;
  struct dirent *result;
  union { // according to "The GNU C Library Reference Manual"
    struct dirent d;
    char b[offsetof(struct dirent, d_name) + NAME_MAX + 1];
    } u;
public:
  cReadDir(const char *Directory);
  ~cReadDir();
  bool Ok(void) { return directory != NULL; }
  struct dirent *Next(void);
  };

class cFile {
private:
  static bool files[];
  static int maxFiles;
  int f;
public:
  cFile(void);
  ~cFile();
  operator int () { return f; }
  bool Open(const char *FileName, int Flags, mode_t Mode = DEFFILEMODE);
  bool Open(int FileDes);
  void Close(void);
  bool IsOpen(void) { return f >= 0; }
  bool Ready(bool Wait = true);
  static bool AnyFileReady(int FileDes = -1, int TimeoutMs = 1000);
  static bool FileReady(int FileDes, int TimeoutMs = 1000);
  static bool FileReadyForWriting(int FileDes, int TimeoutMs = 1000);
  };

class cSafeFile {
private:
  FILE *f;
  char *fileName;
  char *tempName;
public:
  cSafeFile(const char *FileName);
  ~cSafeFile();
  operator FILE* () { return f; }
  bool Open(void);
  bool Close(void);
  };

/// cUnbufferedFile is used for large files that are mainly written or read
/// in a streaming manner, and thus should not be cached.

class cUnbufferedFile {
private:
  int fd;
  off_t curpos;
  off_t cachedstart;
  off_t cachedend;
  off_t begin;
  off_t lastpos;
  off_t ahead;
  size_t readahead;
  size_t written;
  size_t totwritten;
  int FadviseDrop(off_t Offset, off_t Len);
public:
  cUnbufferedFile(void);
  ~cUnbufferedFile();
  int Open(const char *FileName, int Flags, mode_t Mode = DEFFILEMODE);
  int Close(void);
  void SetReadAhead(size_t ra);
  off_t Seek(off_t Offset, int Whence);
  ssize_t Read(void *Data, size_t Size);
  ssize_t Write(const void *Data, size_t Size);
  static cUnbufferedFile *Create(const char *FileName, int Flags, mode_t Mode = DEFFILEMODE);
  };

class cLockFile {
private:
  char *fileName;
  int f;
public:
  cLockFile(const char *Directory);
  ~cLockFile();
  bool Lock(int WaitSeconds = 0);
  void Unlock(void);
  };

class cListObject {
private:
  cListObject *prev, *next;
public:
  cListObject(void);
  virtual ~cListObject();
  virtual int Compare(const cListObject &ListObject) const { return 0; }
      ///< Must return 0 if this object is equal to ListObject, a positive value
      ///< if it is "greater", and a negative value if it is "smaller".
  void Append(cListObject *Object);
  void Insert(cListObject *Object);
  void Unlink(void);
  int Index(void) const;
  cListObject *Prev(void) const { return prev; }
  cListObject *Next(void) const { return next; }
  };

class cListBase {
protected:
  cListObject *objects, *lastObject;
  cListBase(void);
  int count;
public:
  virtual ~cListBase();
  void Add(cListObject *Object, cListObject *After = NULL);
  void Ins(cListObject *Object, cListObject *Before = NULL);
  void Del(cListObject *Object, bool DeleteObject = true);
  virtual void Move(int From, int To);
  void Move(cListObject *From, cListObject *To);
  virtual void Clear(void);
  cListObject *Get(int Index) const;
  int Count(void) const { return count; }
  void Sort(void);
  };

template<class T> class cList : public cListBase {
public:
  T *Get(int Index) const { return (T *)cListBase::Get(Index); }
  T *First(void) const { return (T *)objects; }
  T *Last(void) const { return (T *)lastObject; }
  T *Prev(const T *object) const { return (T *)object->cListObject::Prev(); } // need to call cListObject's members to
  T *Next(const T *object) const { return (T *)object->cListObject::Next(); } // avoid ambiguities in case of a "list of lists"
  };

template<class T> class cVector {
private:
  mutable int allocated;
  mutable int size;
  mutable T *data;
  cVector(const cVector &Vector) {} // don't copy...
  cVector &operator=(const cVector &Vector) { return *this; } // ...or assign this!
  void Realloc(int Index) const
  {
    if (++Index > allocated) {
       data = (T *)realloc(data, Index * sizeof(T));
       for (int i = allocated; i < Index; i++)
           data[i] = T(0);
       allocated = Index;
       }
  }
public:
  cVector(int Allocated = 10)
  {
    allocated = 0;
    size = 0;
    data = NULL;
    Realloc(Allocated);
  }
  virtual ~cVector() { free(data); }
  T& At(int Index) const
  {
    Realloc(Index);
    if (Index >= size)
       size = Index + 1;
    return data[Index];
  }
  const T& operator[](int Index) const
  {
    return At(Index);
  }
  T& operator[](int Index)
  {
    return At(Index);
  }
  int Size(void) const { return size; }
  virtual void Insert(T Data, int Before = 0)
  {
    if (Before < size) {
       Realloc(size);
       memmove(&data[Before + 1], &data[Before], (size - Before) * sizeof(T));
       size++;
       data[Before] = Data;
       }
    else
       Append(Data);
  }
  virtual void Append(T Data)
  {
    if (size >= allocated)
       Realloc(allocated * 4 / 2); // increase size by 50%
    data[size++] = Data;
  }
  virtual void Remove(int Index)
  {
    if (Index < size - 1)
       memmove(&data[Index], &data[Index + 1], (size - Index) * sizeof(T));
    size--;
  }
  virtual void Clear(void)
  {
    size = 0;
  }
  void Sort(__compar_fn_t Compare)
  {
    qsort(data, size, sizeof(T), Compare);
  }
  };

inline int CompareStrings(const void *a, const void *b)
{
  return strcmp(*(const char **)a, *(const char **)b);
}

class cStringList : public cVector<char *> {
public:
  cStringList(int Allocated = 10): cVector<char *>(Allocated) {}
  virtual ~cStringList();
  int Find(const char *s) const;
  void Sort(void) { cVector<char *>::Sort(CompareStrings); }
  virtual void Clear(void);
  };

class cFileNameList : public cStringList {
public:
  cFileNameList(const char *Directory = NULL, bool DirsOnly = false);
  bool Load(const char *Directory, bool DirsOnly = false);
  };

class cHashObject : public cListObject {
  friend class cHashBase;
private:
  unsigned int id;
  cListObject *object;
public:
  cHashObject(cListObject *Object, unsigned int Id) { object = Object; id = Id; }
  cListObject *Object(void) { return object; }
  };

class cHashBase {
private:
  cList<cHashObject> **hashTable;
  int size;
  unsigned int hashfn(unsigned int Id) const { return Id % size; }
protected:
  cHashBase(int Size);
public:
  virtual ~cHashBase();
  void Add(cListObject *Object, unsigned int Id);
  void Del(cListObject *Object, unsigned int Id);
  void Clear(void);
  cListObject *Get(unsigned int Id) const;
  cList<cHashObject> *GetList(unsigned int Id) const;
  };

#define HASHSIZE 512

template<class T> class cHash : public cHashBase {
public:
  cHash(int Size = HASHSIZE) : cHashBase(Size) {}
  T *Get(unsigned int Id) const { return (T *)cHashBase::Get(Id); }
};

#endif //__TOOLS_H