buflib: Move the API back into buflib.h

To minimize code duplication between buflib backends move the
public part of the API to buflib.h. Also rewrote documentation
for the whole API.

Change-Id: I4d7ed6d02084d7130cb41511e63c25ec45b51703

2 files changed, 361 insertions, 323 deletions

diff --git a/firmware/include/buflib.h b/firmware/include/buflib.h
index 36d171963a..32a5a6abe0 100644
--- a/firmware/include/buflib.h
+++ b/firmware/include/buflib.h
@@ -7,6 +7,8 @@
  *                     \/            \/     \/    \/            \/
  * $Id$
  *
+ * Copyright (C) 2009 Andrew Mahone
+ * Copyright (C) 2011 Thomas Martitz
  * Copyright (C) 2023 Aidan MacDonald
  *
  * This program is free software; you can redistribute it and/or
@@ -22,9 +24,366 @@
 #define _BUFLIB_H_
 
 #include "config.h"
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+
+/* Add extra checks to buflib_get_data to catch bad handles */
+//#define BUFLIB_DEBUG_GET_DATA
+
+/* Support integrity check */
+//#define BUFLIB_DEBUG_CHECK_VALID
+
+/* Support debug printing of memory blocks */
+//#define BUFLIB_DEBUG_PRINT
+
+/* Defined by the backend header. */
+struct buflib_context;
+
+/* Buflib callback return codes. */
+#define BUFLIB_CB_OK            0
+#define BUFLIB_CB_CANNOT_MOVE   1
+#define BUFLIB_CB_CANNOT_SHRINK 1
+
+/* Buflib shrink hints. */
+#define BUFLIB_SHRINK_SIZE_MASK (~BUFLIB_SHRINK_POS_MASK)
+#define BUFLIB_SHRINK_POS_FRONT (1u<<31)
+#define BUFLIB_SHRINK_POS_BACK  (1u<<30)
+#define BUFLIB_SHRINK_POS_MASK  (BUFLIB_SHRINK_POS_FRONT|BUFLIB_SHRINK_POS_BACK)
+
+/**
+ * Callbacks run by buflib to manage an allocation.
+ */
+struct buflib_callbacks
+{
+    /**
+     * \brief Called when buflib wants to move the buffer
+     * \param handle    Handle being moved
+     * \param current   Current address of the buffer
+     * \param new       New address the buffer would have after moving
+     * \return BUFLIB_CB_OK - Allow the buffer to be moved.
+     * \return BUFLIB_CB_CANNOT_MOVE - Do not allow the buffer to be moved.
+     *
+     * This callback allows you to fix up any pointers that might
+     * be pointing to the buffer before it is moved. The task of
+     * actually moving the buffer contents is performed by buflib
+     * after the move callback returns, if movement is allowed.
+     *
+     * Care must be taken to ensure that the buffer is not accessed
+     * from outside the move callback until the move is complete. If
+     * this is a concern, eg. due to multi-threaded access, then you
+     * must implement a sync_callback() and guard any access to the
+     * buffer with a lock.
+     *
+     * If the move callback is NULL then buflib will never move
+     * the allocation, as if you returned BUFLIB_CB_CANNOT_MOVE.
+     */
+    int (*move_callback)(int handle, void* current, void* new);
+
+    /**
+     * \brief Called when buflib wants to shrink the buffer
+     * \param handle    Handle to shrink
+     * \param hints     Hints regarding the shrink request
+     * \param start     Current address of the buffer
+     * \param size      Current size of the buffer as seen by buflib.
+     *                  This may be rounded up compared to the nominal
+     *                  allocation size due to alignment requirements.
+     * \return BUFLIB_CB_OK - Was able to shrink the buffer.
+     * \return BUFLIB_CB_CANNOT_SHRINK - Buffer cannot shrink.
+     *
+     * This callback is run by buflib when it runs out of memory
+     * and starts a compaction run. Buflib will not actually try
+     * to shrink or move memory, you must do that yourself and
+     * call buflib_shrink() to report the new start address and
+     * size of the buffer.
+     *
+     * If the shrink callback is NULL then buflib will regard the
+     * buffer as non-shrinkable.
+     */
+    int (*shrink_callback)(int handle, unsigned hints,
+                           void *start, size_t size);
+
+    /**
+     * \brief Called before and after attempting to move the buffer
+     * \param handle    Handle being moved
+     * \param lock      True to lock, false to unlock
+     *
+     * The purpose of this callback is to block access to the buffer
+     * from other threads while a buffer is being moved, using a lock
+     * such as a mutex.
+     *
+     * It is called with `sync_callback(handle, true)` before running
+     * the move callback and `sync_callback(handle, false)` after the
+     * move is complete, regardless of whether the buffer was actually
+     * moved or not.
+     */
+    void (*sync_callback)(int handle, bool lock);
+};
+
+/**
+ * A set of all NULL callbacks for use with allocations that need to stay
+ * locked in RAM and not moved or shrunk. These type of allocations should
+ * be avoided as much as possible to avoid memory fragmentation but it can
+ * suitable for short-lived allocations.
+ *
+ * \note Use of this is discouraged. Prefer to use normal moveable
+ *       allocations and pin them.
+ */
+extern struct buflib_callbacks buflib_ops_locked;
+
+/**
+ * \brief Intialize a buflib context
+ * \param ctx       Context to initialize
+ * \param buf       Buffer which will be used as the context's memory pool
+ * \param size      Size of the buffer
+ */
+void buflib_init(struct buflib_context *ctx, void *buf, size_t size);
+
+/**
+ * Returns the amount of unallocated bytes. It does not mean this amount
+ * can be actually allocated because they might not be contiguous.
+ */
+size_t buflib_available(struct buflib_context *ctx);
+
+/**
+ * Returns the size of the largest possible contiguous allocation, given
+ * the current state of the memory pool. A larger allocation may still
+ * succeed if compaction is able to create a larger contiguous area.
+ */
+size_t buflib_allocatable(struct buflib_context *ctx);
+
+/**
+ * \brief Relocate the buflib memory pool to a new address
+ * \param ctx       Context to relocate
+ * \param buf       New memory pool address
+ * \return True if relocation should proceed, false if it cannot.
+ *
+ * Updates all pointers inside the buflib context to point to a new pool
+ * address. You must call this function before moving the pool and move
+ * the data manually afterwards only if this function returns true.
+ *
+ * This is intended from a move_callback() in buflib-on-buflib scenarios,
+ * where the memory pool of the "inner" buflib is allocated from an "outer"
+ * buflib.
+ *
+ * \warning This does not run any move callbacks, so it is not safe to
+ *          use if any allocations require them.
+ */
+bool buflib_context_relocate(struct buflib_context *ctx, void *buf);
+
+/**
+ * \brief Allocate memory from buflib
+ * \param ctx       Context to allocate from
+ * \param size      Allocation size
+ * \return Handle for the allocation (> 0) or a negative value on error
+ *
+ * This is the same as calling buflib_alloc_ex() with a NULL callbacks
+ * struct. The resulting allocation can be moved by buflib; use pinning
+ * if you need to prevent moves.
+ *
+ * Note that zero is not a valid handle, and will never be returned by
+ * this function. However, this may change, and you should treat a zero
+ * or negative return value as an allocation failure.
+ */
+int buflib_alloc(struct buflib_context *ctx, size_t size);
+
+/**
+ * \brief Allocate memory from buflib with custom buffer ops
+ * \param ctx       Context to allocate from
+ * \param size      Allocation size
+ * \param ops       Pointer to ops struct or NULL if no ops are needed.
+ * \return Handle for the allocation (> 0) or a negative value on error.
+ *
+ * Use this if you need to pass custom callbacks for responding to buflib
+ * move or shrink operations. Passing a NULL ops pointer means the buffer
+ * can be moved by buflib at any time.
+ *
+ * Note that zero is not a valid handle, and will never be returned by
+ * this function. However, this may change, and you should treat a zero
+ * or negative return value as an allocation failure.
+ */
+int buflib_alloc_ex(struct buflib_context *ctx, size_t size,
+                    struct buflib_callbacks *ops);
+
+/**
+ * \brief Attempt a maximum size allocation
+ * \param ctx       Context to allocate from
+ * \param size      Size of the allocation will be written here on success.
+ * \param ops       Pointer to ops struct or NULL if no ops are needed.
+ * \return Handle for the allocation (> 0) or a negative value on error.
+ *
+ * Buflib will attempt to compact and shrink other allocations as much as
+ * possible and then allocate the largest contigous free area. Since this
+ * will consume effectively *all* available memory, future allocations are
+ * likely to fail.
+ *
+ * \note There is rarely any justification to use this with the core_alloc
+ *       context due to the impact it has on the entire system. You should
+ *       change your code if you think you need this. Of course, if you are
+ *       using a private buflib context then this warning does not apply.
+ */
+int buflib_alloc_maximum(struct buflib_context *ctx,
+                         size_t *size, struct buflib_callbacks *ops);
+
+/**
+ * \brief Reduce the size of a buflib allocation
+ * \param ctx       Buflib context of the allocation
+ * \param handle    Handle identifying the allocation
+ * \param newstart  New start address. Must be within the current bounds
+ *                  of the allocation, as returned by buflib_get_data().
+ * \param new_size  New size of the buffer.
+ * \return True if shrinking was successful; otherwise, returns false and
+ *         does not modify the allocation.
+ *
+ * Shrinking always succeeds provided the new allocation is contained
+ * within the current allocation. A failure is always a programming
+ * error, so you need not check for it and in the future the failure
+ * case may be changed to a panic or undefined behavior with no return
+ * code.
+ *
+ * The new start address and size need not have any particular alignment,
+ * however buflib cannot work with unaligned addresses so there is rarely
+ * any purpose to creating unaligned allocations.
+ *
+ * Shrinking is typically done from a shrink_callback(), but can be done
+ * at any time if you want to reduce the size of a buflib allocation.
+ */
+bool buflib_shrink(struct buflib_context *ctx, int handle,
+                   void *newstart, size_t new_size);
+
+/**
+ * \brief Increment an allocation's pin count
+ * \param ctx       Buflib context of the allocation
+ * \param handle    Handle identifying the allocation
+ *
+ * The pin count acts like a reference count. Buflib will not attempt to
+ * move any buffer with a positive pin count, nor invoke any move or sync
+ * callbacks. Hence, when pinned, it is safe to hold pointers to a buffer
+ * across yields or use them for I/O.
+ *
+ * Note that shrink callbacks can still be invoked for pinned handles.
+ */
+void buflib_pin(struct buflib_context *ctx, int handle);
+
+/**
+ * \brief Decrement an allocation's pin count
+ * \param ctx       Buflib context of the allocation
+ * \param handle    Handle identifying the allocation
+ */
+void buflib_unpin(struct buflib_context *ctx, int handle);
+
+/**
+ * \brief Return the pin count of an allocation
+ * \param ctx       Buflib context of the allocation
+ * \param handle    Handle identifying the allocation
+ * \return Current pin count; zero means the handle is not pinned.
+ */
+unsigned buflib_pin_count(struct buflib_context *ctx, int handle);
+
+/**
+ * \brief Free an allocation and return its memory to the pool
+ * \param ctx       Buflib context of the allocation
+ * \param handle    Handle identifying the allocation
+ * \return Always returns zero (zero is not a valid handle, so this can
+ *         be used to invalidate the variable containing the handle).
+ */
+int buflib_free(struct buflib_context *context, int handle);
+
+/**
+ * \brief Get a pointer to the buffer for an allocation
+ * \param ctx       Buflib context of the allocation
+ * \param handle    Handle identifying the allocation
+ * \return Pointer to the allocation's memory.
+ *
+ * Note that buflib can move allocations in order to free up space when
+ * making new allocations. For this reason, it's unsafe to hold a pointer
+ * to a buffer across a yield() or any other operation that can cause a
+ * context switch. This includes any function that may block, and even
+ * some functions that might not block -- eg. if a low priority thread
+ * acquires a mutex, calling mutex_unlock() may trigger a context switch
+ * to a higher-priority thread.
+ *
+ * buflib_get_data() is a very cheap operation, however, costing only
+ * a few pointer lookups. Don't hesitate to use it extensively.
+ *
+ * If you need to hold a pointer across a possible context switch, pin
+ * the handle with buflib_pin() to prevent the buffer from being moved.
+ * This is required when doing I/O into buflib allocations, for example.
+ */
+#ifdef BUFLIB_DEBUG_GET_DATA
+void *buflib_get_data(struct buflib_context *ctx, int handle);
+#else
+static inline void *buflib_get_data(struct buflib_context *ctx, int handle);
+#endif
+
+/**
+ * \brief Shift allocations up to free space at the start of the pool
+ * \param ctx       Context to operate on
+ * \param size      Indicates number of bytes to free up, or 0 to free
+ *                  up as much as possible. On return, the actual number
+ *                  of bytes freed is written here.
+ * \return Pointer to the start of the free area
+ *
+ * If `*size` is non-zero, the actual amount of space freed up might
+ * be less than `*size`.
+ *
+ * \warning This will move data around in the pool without calling any
+ *          move callbacks!
+ * \warning This function is deprecated and will eventually be removed.
+ */
+void* buflib_buffer_out(struct buflib_context *ctx, size_t *size);
+
+/**
+ * \brief Shift allocations down into free space below the pool
+ * \param ctx       Context to operate on
+ * \param size      Number of bytes to add to the pool.
+ *
+ * This operation should only be used to return memory that was previously
+ * taken from the pool with buflib_buffer_out(), by passing the same size
+ * that you got from that function.
+ *
+ * \warning This will move data around in the pool without calling any
+ *          move callbacks!
+ * \warning This function is deprecated and will eventually be removed.
+ */
+void buflib_buffer_in(struct buflib_context *ctx, int size);
+
+#ifdef BUFLIB_DEBUG_PRINT
+/**
+ * Return the number of blocks in the buffer, allocated or unallocated.
+ *
+ * Only available if BUFLIB_DEBUG_PRINT is defined.
+ */
+int buflib_get_num_blocks(struct buflib_context *ctx);
+
+/**
+ * Write a string describing the block at index block_num to the
+ * provided buffer. The buffer will always be null terminated and
+ * there is no provision to detect truncation. (A 40-byte buffer
+ * is enough to contain any returned string.)
+ *
+ * Returns false if the block index is out of bounds, and writes
+ * an empty string.
+ *
+ * Only available if BUFLIB_DEBUG_PRINT is defined.
+ */
+bool buflib_print_block_at(struct buflib_context *ctx, int block_num,
+                           char *buf, size_t bufsize);
+#endif
+
+#ifdef BUFLIB_DEBUG_CHECK_VALID
+/**
+ * Check integrity of given buflib context
+ */
+void buflib_check_valid(struct buflib_context *ctx);
+#endif
 
 #if CONFIG_BUFLIB_BACKEND == BUFLIB_BACKEND_MEMPOOL
 #include "buflib_mempool.h"
 #endif
 
+#ifndef BUFLIB_ALLOC_OVERHEAD
+# define BUFLIB_ALLOC_OVERHEAD 0
+#endif
+
 #endif /* _BUFLIB_H_ */
diff --git a/firmware/include/buflib_mempool.h b/firmware/include/buflib_mempool.h
index f261d4abda..4b01b629c3 100644
--- a/firmware/include/buflib_mempool.h
+++ b/firmware/include/buflib_mempool.h
@@ -30,19 +30,6 @@
 # error "include buflib.h instead"
 #endif
 
-#include <stdint.h>
-#include <stdbool.h>
-#include <string.h>
-
-/* add extra checks to buflib_get_data to catch bad handles */
-//#define BUFLIB_DEBUG_GET_DATA
-
-/* support integrity check */
-//#define BUFLIB_DEBUG_CHECK_VALID
-
-/* support debug printing of memory blocks */
-//#define BUFLIB_DEBUG_PRINT
-
 union buflib_data
 {
     intptr_t val;                 /* length of the block in n*sizeof(union buflib_data).
@@ -65,321 +52,13 @@ struct buflib_context
     bool compact;
 };
 
-/**
- * This declares the minimal overhead that is required per alloc. These
- * are bytes that are allocated from the context's pool in addition
- * to the actually requested number of bytes.
- *
- * The total number of bytes consumed by an allocation is
- * BUFLIB_ALLOC_OVERHEAD + requested bytes + pad to pointer size
- */
-#define BUFLIB_ALLOC_OVERHEAD (4*sizeof(union buflib_data))
-
-/**
- * Callbacks used by the buflib to inform allocation that compaction
- * is happening (before data is moved)
- *
- * Note that buflib tries to move to satisfy new allocations before shrinking.
- * So if you have something to resize try to do it outside of the callback.
- *
- * Regardless of the above, if the allocation is SHRINKABLE, but not
- * MUST_NOT_MOVE buflib will move the allocation before even attempting to
- * shrink.
- */
-struct buflib_callbacks {
-    /**
-     * This is called before data is moved. Use this to fix up any cached
-     * pointers pointing to inside the allocation. The size is unchanged.
-     *
-     * This is not needed if you don't cache the data pointer (but always
-     * call buflib_get_data()) and don't pass pointer to the data to yielding
-     * functions.
-     *
-     * handle: The corresponding handle
-     * current: The current start of the allocation
-     * new: The new start of the allocation, after data movement
-     *
-     * Return: Return BUFLIB_CB_OK, or BUFLIB_CB_CANNOT_MOVE if movement
-     * is impossible at this moment.
-     *
-     * If NULL: this allocation must not be moved around
-     * by the buflib when compaction occurs. Attention: Don't confuse
-     * that with passing NULL for the whole callback structure
-     * to buflib_alloc_ex(). This would enable moving buffers by default.
-     * You have to pass NULL inside the "struct buflib_callbacks" structure.
-     */
-    int (*move_callback)(int handle, void* current, void* new);
-    /**
-     * This is called when the buflib desires to shrink a buffer
-     * in order to satisfy new allocation. This happens when buflib runs
-     * out of memory, e.g. because buflib_alloc_maximum() was called.
-     * Move data around as you need to make space and call core_shrink() as
-     * appropriate from within the callback to complete the shrink operation.
-     * buflib will not move data as part of shrinking.
-     *
-     * hint: bit mask containing hints on how shrinking is desired (see below)
-     * handle: The corresponding handle
-     * start: The old start of the allocation
-     *
-     * Return: Return BUFLIB_CB_OK, or BUFLIB_CB_CANNOT_SHRINK if shirinking
-     * is impossible at this moment.
-     *
-     * if NULL: this allocation cannot be resized.
-     * It is recommended that allocation that must not move are
-     * at least shrinkable
-     */
-    int (*shrink_callback)(int handle, unsigned hints, void* start, size_t old_size);
-    /**
-     * This is called when special steps must be taken for synchronization
-     * both before the move_callback is called and after the data has been
-     * moved.
-     */
-    void (*sync_callback)(int handle, bool sync_on);
-};
-
-/** A set of all NULL callbacks for use with allocations that need to stay
- * locked in RAM and not moved or shrunk. These type of allocations should
- * be avoided as much as possible to avoid memory fragmentation but it can
- * suitable for short-lived allocations. */
-extern struct buflib_callbacks buflib_ops_locked;
-
-#define BUFLIB_SHRINK_SIZE_MASK (~BUFLIB_SHRINK_POS_MASK)
-#define BUFLIB_SHRINK_POS_FRONT (1u<<31)
-#define BUFLIB_SHRINK_POS_BACK  (1u<<30)
-#define BUFLIB_SHRINK_POS_MASK  (BUFLIB_SHRINK_POS_FRONT|BUFLIB_SHRINK_POS_BACK)
-
-/**
- * Possible return values for the callbacks, some of them can cause
- * compaction to fail and therefore new allocations to fail
- */
-/* Everything alright */
-#define BUFLIB_CB_OK 0
-/* Tell buflib that moving failed. Buflib may retry to move at any point */
-#define BUFLIB_CB_CANNOT_MOVE 1
-/* Tell buflib that resizing failed, possibly future making allocations fail */
-#define BUFLIB_CB_CANNOT_SHRINK 1
-
-/**
- * Initializes buflib with a caller allocated context instance and memory pool.
- *
- * The buflib_context instance needs to be passed to every other buflib
- * function. It's should be considered opaque, even though it is not yet
- * (that's to make inlining core_get_data() possible). The documentation
- * of the other functions will not describe the context
- * instance parameter further as it's obligatory.
- *
- * context: The new buflib instance to be initialized, allocated by the caller
- * size: The size of the memory pool
- */
-void buflib_init(struct buflib_context *context, void *buf, size_t size);
-
-
-/**
- * Returns the amount of unallocated bytes. It does not mean this amount
- * can be actually allocated because they might not be contiguous.
- *
- * Returns: The number of unallocated bytes in the memory pool.
- */
-size_t buflib_available(struct buflib_context *ctx);
-
-/**
- * Returns the biggest possible allocation that can be determined to succeed.
- *
- * Returns: The amount of bytes of the biggest unallocated, contiguous region.
- */
-size_t buflib_allocatable(struct buflib_context *ctx);
-
-/**
- * Relocates the fields in *ctx to the new buffer position pointed to by buf.
- * This does _not_ move any data but updates the pointers. The data has
- * to be moved afterwards manually and only if this function returned true.
- *
- * This is intended to be called from within a move_callback(), for
- * buflib-on-buflib scenarios (i.e. a new buflib instance backed by a buffer
- * that was allocated by another buflib instance). Be aware that if the parent
- * move_callback() moves the underlying buffer _no_ move_callback() of the
- * underlying buffer are called.
- *
- * Returns true of the relocation was successful. If it returns false no
- * change to *ctx was made.
- */
-bool buflib_context_relocate(struct buflib_context *ctx, void *buf);
-
-/**
- * Allocates memory from buflib's memory pool
- *
- * size: How many bytes to allocate
- *
- * This function passes NULL for the callback structure "ops", so buffers
- * are movable. Don't pass them to functions that yield().
- *
- * Returns: A positive integer handle identifying this allocation, or
- * a negative value on error (0 is also not a valid handle)
- */
-int buflib_alloc(struct buflib_context *context, size_t size);
-
+#define BUFLIB_ALLOC_OVERHEAD (4 * sizeof(union buflib_data))
 
-/**
- * Allocates memory from the buflib's memory pool with additional callbacks
- * and flags
- *
- * size: How many bytes to allocate
- * ops: a struct with pointers to callback functions (see above).
- *      if "ops" is NULL: Buffer is movable.
- *
- * Returns: A positive integer handle identifying this allocation, or
- * a negative value on error (0 is also not a valid handle)
- */
-int buflib_alloc_ex(struct buflib_context *ctx, size_t size,
-                    struct buflib_callbacks *ops);
-
-
-/**
- * Gets all available memory from buflib, for temporary use.
- *
- * Since this effectively makes all future allocations fail (unless
- * another allocation is freed in the meantime), you should definitely provide
- * a shrink callback if you plan to hold the buffer for a longer period. This
- * will allow buflib to permit allocations by shrinking the buffer returned by
- * this function.
- *
- * Note that this might return many more bytes than buflib_available() or
- * buflib_allocatable() return, because it aggressively compacts the pool
- * and even shrinks other allocations. However, do not depend on this behavior,
- * it may change.
- *
- * size: The actual size will be returned into size
- * ops: a struct with pointers to callback functions
- *
- * Returns: A positive integer handle identifying this allocation, or
- * a negative value on error (0 is also not a valid handle)
- */
-int buflib_alloc_maximum(struct buflib_context* ctx,
-                         size_t *size, struct buflib_callbacks *ops);
-
-/**
- * Queries the data pointer for the given handle. It's actually a cheap
- * operation, don't hesitate using it extensively.
- *
- * Notice that you need to re-query after every direct or indirect yield(),
- * because compaction can happen by other threads which may get your data
- * moved around (or you can get notified about changes by callbacks,
- * see further above).
- *
- * handle: The handle corresponding to the allocation
- *
- * Returns: The start pointer of the allocation
- */
-#ifdef BUFLIB_DEBUG_GET_DATA
-void *buflib_get_data(struct buflib_context *ctx, int handle);
-#else
+#ifndef BUFLIB_DEBUG_GET_DATA
 static inline void *buflib_get_data(struct buflib_context *ctx, int handle)
 {
     return (void *)ctx->handle_table[-handle].alloc;
 }
 #endif
 
-/**
- * Shrink the memory allocation associated with the given handle
- * Mainly intended to be used with the shrink callback, but it can also
- * be called outside as well, e.g. to give back buffer space allocated
- * with buflib_alloc_maximum().
- *
- * Note that you must move/copy data around yourself before calling this,
- * buflib will not do this as part of shrinking.
- *
- * handle: The handle identifying this allocation
- * new_start: the new start of the allocation
- * new_size: the new size of the allocation
- *
- * Returns: true if shrinking was successful. Otherwise it returns false,
- * without having modified memory.
- *
- */
-bool buflib_shrink(struct buflib_context *ctx, int handle, void* newstart, size_t new_size);
-
-/**
- * Increment the pin count for a handle. When pinned the handle will not
- * be moved and move callbacks will not be triggered, allowing a pointer
- * to the buffer to be kept across yields or used for I/O.
- *
- * Note that shrink callbacks can still be invoked for pinned handles.
- */
-void buflib_pin(struct buflib_context *ctx, int handle);
-
-/**
- * Decrement the pin count for a handle.
- */
-void buflib_unpin(struct buflib_context *ctx, int handle);
-
-/**
- * Get the current pin count of a handle. Zero means the handle is not pinned.
- */
-unsigned buflib_pin_count(struct buflib_context *ctx, int handle);
-
-/**
- * Frees memory associated with the given handle
- *
- * Returns: 0 (to invalidate handles in one line, 0 is not a valid handle)
- */
-int buflib_free(struct buflib_context *context, int handle);
-
-/**
- * Moves the underlying buflib buffer up by size bytes (as much as
- * possible for size == 0) without moving the end. This effectively
- * reduces the available space by taking away manageable space from the
- * front. This space is not available for new allocations anymore.
- *
- * To make space available in the front, everything is moved up.
- * It does _NOT_ call the move callbacks
- * 
- *
- * size: size in bytes to move the buffer up (take away). The actual
- * bytes moved is returned in this
- * Returns: The new start of the underlying buflib buffer
- */
-void* buflib_buffer_out(struct buflib_context *ctx, size_t *size);
-
-/**
- * Moves the underlying buflib buffer down by size bytes without
- * moving the end. This grows the buflib buffer by adding space to the front.
- * The new bytes are available for new allocations.
- *
- * Everything is moved down, and the new free space will be in the middle.
- * It does _NOT_ call the move callbacks.
- *
- * size: size in bytes to move the buffer down (new free space)
- */
-void buflib_buffer_in(struct buflib_context *ctx, int size);
-
-#ifdef BUFLIB_DEBUG_PRINT
-/**
- * Return the number of blocks in the buffer, allocated or unallocated.
- *
- * Only available if BUFLIB_DEBUG_PRINT is defined.
- */
-int buflib_get_num_blocks(struct buflib_context *ctx);
-
-/**
- * Write a string describing the block at index block_num to the
- * provided buffer. The buffer will always be null terminated and
- * there is no provision to detect truncation. (A 40-byte buffer
- * is enough to contain any returned string.)
- *
- * Returns false if the block index is out of bounds, and writes
- * an empty string.
- *
- * Only available if BUFLIB_DEBUG_PRINT is defined.
- */
-bool buflib_print_block_at(struct buflib_context *ctx, int block_num,
-                           char *buf, size_t bufsize);
-#endif
-
-#ifdef BUFLIB_DEBUG_CHECK_VALID
-/**
- * Check integrity of given buflib context
- */
-void buflib_check_valid(struct buflib_context *ctx);
-#endif
-
 #endif /* _BUFLIB_MEMPOOL_H_ */