Added SBuffer class to hold a writable buffer that will

be used to construct an SString.
SContainer is superclass of both SBuffer and SString and
holds a char array allocation and size.

1 files changed, 124 insertions, 43 deletions

diff --git a/include/SString.h b/include/SString.h
index 659f8b0c8..afe1a902c 100644
--- a/include/SString.h
+++ b/include/SString.h
@@ -2,7 +2,7 @@
 /** @file SString.h
  ** A simple string class.
  **/
-// Copyright 1998-2001 by Neil Hodgson <neilh@scintilla.org>
+// Copyright 1998-2004 by Neil Hodgson <neilh@scintilla.org>
 // The License.txt file describes the conditions under which this software may be distributed.
 
 #ifndef SSTRING_H
@@ -18,23 +18,117 @@ bool EqualCaseInsensitive(const char *a, const char *b);
 // An SString may contain embedded nul characters.
 
 /**
- * @brief A simple string class.
- *
- * Hold the length of the string for quick operations,
- * can have a buffer bigger than the string to avoid too many memory allocations and copies.
- * May have embedded zeroes as a result of @a substitute, but relies too heavily on C string
- * functions to allow reliable manipulations of these strings, other than simple appends, etc.
- **/
-class SString {
+ * Base class from which the two other classes (SBuffer & SString)
+ * are derived.
+ */
+class SContainer {
 public:
 	/** Type of string lengths (sizes) and positions (indexes). */
 	typedef size_t lenpos_t;
 	/** Out of bounds value indicating that the string argument should be measured. */
 	enum { measure_length=0xffffffffU};
 
-private:
+protected:
 	char *s;				///< The C string
 	lenpos_t sSize;			///< The size of the buffer, less 1: ie. the maximum size of the string
+
+	SContainer() : s(0), sSize(0) {}
+	~SContainer() {
+		delete []s;	// Suppose it was allocated using StringAllocate
+		s = 0;
+		sSize = 0;
+	}
+	/** Size of buffer. */
+	lenpos_t size() const {
+		if (s) {
+			return sSize;
+		} else {
+			return 0;
+		}
+	}
+public:
+	/**
+	 * Allocate uninitialized memory big enough to fit a string of the given length.
+	 * @return the pointer to the new string
+	 */
+	static char *StringAllocate(lenpos_t len);
+	/**
+	 * Duplicate a buffer/C string.
+	 * Allocate memory of the given size, or big enough to fit the string if length isn't given;
+	 * then copy the given string in the allocated memory.
+	 * @return the pointer to the new string
+	 */
+	static char *StringAllocate(
+		const char *s,			///< The string to duplicate
+		lenpos_t len=measure_length);	///< The length of memory to allocate. Optional.
+};
+
+
+/**
+ * @brief A string buffer class.
+ *
+ * Main use is to ask an API the length of a string it can provide,
+ * then to allocate a buffer of the given size, and to provide this buffer
+ * to the API to put the string.
+ * This class is intended to be shortlived, to be transformed as SString
+ * as soon as it holds the string, so it has little members.
+ * Note: we assume the buffer is filled by the API. If the length can be shorter,
+ * we should set sLen to strlen(sb.ptr()) in related SString constructor and assignment.
+ */
+class SBuffer : protected SContainer {
+public:
+	SBuffer(lenpos_t len) {
+		s = StringAllocate(len);
+		if (s) {
+			*s = '\0';
+		sSize = len;
+		} else {
+			sSize = 0;
+		}
+	}
+private:
+	/// Copy constructor
+	// Here only to be on the safe size, user should avoid returning SBuffer values.
+	SBuffer(const SBuffer &source) : SContainer() {
+		s = StringAllocate(source.s, source.sSize);
+		sSize = (s) ? source.sSize : 0;
+	}
+	/// Default assignment operator
+	// Same here, shouldn't be used
+	SBuffer &operator=(const SBuffer &source) {
+		if (this != &source) {
+			delete []s;
+			s = StringAllocate(source.s, source.sSize);
+			sSize = (s) ? source.sSize : 0;
+		}
+		return *this;
+	}
+public:
+	/** Provide direct read/write access to buffer. */
+	char *ptr() {
+	    return s;
+	}
+	/** Ownership of the buffer have been taken, so release it. */
+	void reset() {
+		s = 0;
+		sSize = 0;
+	}
+	/** Size of buffer. */
+	lenpos_t size() const {
+		return SContainer::size();
+	}
+};
+
+
+/**
+ * @brief A simple string class.
+ *
+ * Hold the length of the string for quick operations,
+ * can have a buffer bigger than the string to avoid too many memory allocations and copies.
+ * May have embedded zeroes as a result of @a substitute, but relies too heavily on C string
+ * functions to allow reliable manipulations of these strings, other than simple appends, etc.
+ */
+class SString : protected SContainer {
 	lenpos_t sLen;			///< The size of the string in s
 	lenpos_t sizeGrowth;	///< Minimum growth size when appending strings
 	enum { sizeGrowthDefault = 64 };
@@ -43,27 +137,29 @@ private:
 	SString &assign(const char *sOther, lenpos_t sSize_=measure_length);
 
 public:
-	SString() : s(0), sSize(0), sLen(0), sizeGrowth(sizeGrowthDefault) {
-	}
-	SString(const SString &source) : sizeGrowth(sizeGrowthDefault) {
-		s = StringAllocate(source.s);
-		sSize = sLen = (s) ? strlen(s) : 0;
+	SString() : sLen(0), sizeGrowth(sizeGrowthDefault) {}
+	SString(const SString &source) : SContainer(), sizeGrowth(sizeGrowthDefault) {
+		s = StringAllocate(source.s, source.sLen);
+		sSize = sLen = (s) ? source.sLen : 0;
 	}
 	SString(const char *s_) : sizeGrowth(sizeGrowthDefault) {
 		s = StringAllocate(s_);
 		sSize = sLen = (s) ? strlen(s) : 0;
 	}
+	SString(SBuffer &buf) : sizeGrowth(sizeGrowthDefault) {
+		s = buf.ptr();
+		sSize = sLen = buf.size();
+		// Consumes the given buffer!
+		buf.reset();
+	}
 	SString(const char *s_, lenpos_t first, lenpos_t last) : sizeGrowth(sizeGrowthDefault) {
 		// note: expects the "last" argument to point one beyond the range end (a la STL iterators)
 		s = StringAllocate(s_ + first, last - first);
-		sSize = sLen = (s) ? strlen(s) : 0;
+		sSize = sLen = (s) ? last - first : 0;
 	}
 	SString(int i);
 	SString(double d, int precision);
 	~SString() {
-		delete []s;
-		s = 0;
-		sSize = 0;
 		sLen = 0;
 	}
 	void clear() {
@@ -74,21 +170,22 @@ public:
 	}
 	/** Size of buffer. */
 	lenpos_t size() const {
-		if (s)
-			return sSize;
-		else
-			return 0;
+		return SContainer::size();
 	}
 	/** Size of string in buffer. */
 	lenpos_t length() const {
 		return sLen;
 	}
+	/** Read access to a character of the string. */
+	char operator[](lenpos_t i) const {
+		return (s && i < sSize) ? s[i] : '\0';
+	}
 	SString &operator=(const char *source) {
 		return assign(source);
 	}
 	SString &operator=(const SString &source) {
 		if (this != &source) {
-			assign(source.c_str(), source.sLen);
+			assign(source.s, source.sLen);
 		}
 		return *this;
 	}
@@ -129,9 +226,6 @@ public:
 		sLen = 0;
 		return sRet;
 	}
-	char operator[](lenpos_t i) const {
-		return (s && i < sSize)	? s[i] : '\0';
-	}
 	SString substr(lenpos_t subPos, lenpos_t subLen=measure_length) const;
 	SString &lowercase(lenpos_t subPos = 0, lenpos_t subLen=measure_length);
 	SString &uppercase(lenpos_t subPos = 0, lenpos_t subLen=measure_length);
@@ -179,22 +273,9 @@ public:
 	int remove(const char *sFind) {
 		return substitute(sFind, "");
 	}
-	/**
-	 * Duplicate a C string.
-	 * Allocate memory of the given size, or big enough to fit the string if length isn't given;
-	 * then copy the given string in the allocated memory.
-	 * @return the pointer to the new string
-	 */
-	static char *StringAllocate(
-		const char *s,			///< The string to duplicate
-		lenpos_t len=measure_length);	///< The length of memory to allocate. Optional.
-	/**
-	 * Allocate uninitialized memory big enough to fit a string of the given length
-	 * @return the pointer to the new string
-	 */
-	static char *StringAllocate(lenpos_t len);
 };
 
+
 /**
  * Duplicate a C string.
  * Allocate memory of the given size, or big enough to fit the string if length isn't given;
@@ -203,9 +284,9 @@ public:
  */
 inline char *StringDup(
 	const char *s,			///< The string to duplicate
-	SString::lenpos_t len=SString::measure_length)	///< The length of memory to allocate. Optional.
+	SContainer::lenpos_t len=SContainer::measure_length)	///< The length of memory to allocate. Optional.
 {
-	return SString::StringAllocate(s, len);
+	return SContainer::StringAllocate(s, len);
 }
 
 #endif