compiler: Move blob up a level

We're going to want to use the blob for Vulkan pipeline caching so it
makes sense to have it in libcompiler not libglsl.

Reviewed-by: Nicolai Hähnle <[email protected]>
Reviewed-by: Jordan Justen <[email protected]>

1 files changed, 307 insertions, 0 deletions

diff --git a/src/compiler/blob.h b/src/compiler/blob.h
new file mode 100644
index 00000000000..4cbbb01b15d
--- /dev/null
+++ b/src/compiler/blob.h
@@ -0,0 +1,307 @@
+/*
+ * Copyright © 2014 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef BLOB_H
+#define BLOB_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* The blob functions implement a simple, low-level API for serializing and
+ * deserializing.
+ *
+ * All objects written to a blob will be serialized directly, (without any
+ * additional meta-data to describe the data written). Therefore, it is the
+ * caller's responsibility to ensure that any data can be read later, (either
+ * by knowing exactly what data is expected, or by writing to the blob
+ * sufficient meta-data to describe what has been written).
+ *
+ * A blob is efficient in that it dynamically grows by doubling in size, so
+ * allocation costs are logarithmic.
+ */
+
+struct blob {
+   /* The data actually written to the blob. */
+   uint8_t *data;
+
+   /** Number of bytes that have been allocated for \c data. */
+   size_t allocated;
+
+   /** The number of bytes that have actual data written to them. */
+   size_t size;
+
+   /**
+    * True if we've ever failed to realloc or if we go pas the end of a fixed
+    * allocation blob.
+    */
+   bool out_of_memory;
+};
+
+/* When done reading, the caller can ensure that everything was consumed by
+ * checking the following:
+ *
+ *   1. blob->current should be equal to blob->end, (if not, too little was
+ *      read).
+ *
+ *   2. blob->overrun should be false, (otherwise, too much was read).
+ */
+struct blob_reader {
+   uint8_t *data;
+   uint8_t *end;
+   uint8_t *current;
+   bool overrun;
+};
+
+/**
+ * Create a new, empty blob.
+ *
+ * \return The new blob, (or NULL in case of allocation failure).
+ */
+struct blob *
+blob_create(void);
+
+/**
+ * Destroy a blob and free its memory.
+ */
+static inline void
+blob_destroy(struct blob *blob)
+{
+   free(blob->data);
+   free(blob);
+}
+
+/**
+ * Add some unstructured, fixed-size data to a blob.
+ *
+ * \return True unless allocation failed.
+ */
+bool
+blob_write_bytes(struct blob *blob, const void *bytes, size_t to_write);
+
+/**
+ * Reserve space in \blob for a number of bytes.
+ *
+ * Space will be allocated within the blob for these byes, but the bytes will
+ * be left uninitialized. The caller is expected to use the return value to
+ * write directly (and immediately) to these bytes.
+ *
+ * \note The return value is valid immediately upon return, but can be
+ * invalidated by any other call to a blob function. So the caller should call
+ * blob_reserve_byes immediately before writing through the returned pointer.
+ *
+ * This function is intended to be used when interfacing with an existing API
+ * that is not aware of the blob API, (so that blob_write_bytes cannot be
+ * called).
+ *
+ * \return A pointer to space allocated within \blob to which \to_write bytes
+ * can be written, (or NULL in case of any allocation error).
+ */
+uint8_t *
+blob_reserve_bytes(struct blob *blob, size_t to_write);
+
+/**
+ * Overwrite some data previously written to the blob.
+ *
+ * Writes data to an existing portion of the blob at an offset of \offset.
+ * This data range must have previously been written to the blob by one of the
+ * blob_write_* calls.
+ *
+ * For example usage, see blob_overwrite_uint32
+ *
+ * \return True unless the requested offset or offset+to_write lie outside
+ * the current blob's size.
+ */
+bool
+blob_overwrite_bytes(struct blob *blob,
+                     size_t offset,
+                     const void *bytes,
+                     size_t to_write);
+
+/**
+ * Add a uint32_t to a blob.
+ *
+ * \note This function will only write to a uint32_t-aligned offset from the
+ * beginning of the blob's data, so some padding bytes may be added to the
+ * blob if this write follows some unaligned write (such as
+ * blob_write_string).
+ *
+ * \return True unless allocation failed.
+ */
+bool
+blob_write_uint32(struct blob *blob, uint32_t value);
+
+/**
+ * Overwrite a uint32_t previously written to the blob.
+ *
+ * Writes a uint32_t value to an existing portion of the blob at an offset of
+ * \offset.  This data range must have previously been written to the blob by
+ * one of the blob_write_* calls.
+ *
+ *
+ * The expected usage is something like the following pattern:
+ *
+ *	size_t offset;
+ *
+ *	offset = blob->size;
+ *	blob_write_uint32 (blob, 0); // placeholder
+ *	... various blob write calls, writing N items ...
+ *	blob_overwrite_uint32 (blob, offset, N);
+ *
+ * \return True unless the requested position or position+to_write lie outside
+ * the current blob's size.
+ */
+bool
+blob_overwrite_uint32(struct blob *blob,
+                      size_t offset,
+                      uint32_t value);
+
+/**
+ * Add a uint64_t to a blob.
+ *
+ * \note This function will only write to a uint64_t-aligned offset from the
+ * beginning of the blob's data, so some padding bytes may be added to the
+ * blob if this write follows some unaligned write (such as
+ * blob_write_string).
+ *
+ * \return True unless allocation failed.
+ */
+bool
+blob_write_uint64(struct blob *blob, uint64_t value);
+
+/**
+ * Add an intptr_t to a blob.
+ *
+ * \note This function will only write to an intptr_t-aligned offset from the
+ * beginning of the blob's data, so some padding bytes may be added to the
+ * blob if this write follows some unaligned write (such as
+ * blob_write_string).
+ *
+ * \return True unless allocation failed.
+ */
+bool
+blob_write_intptr(struct blob *blob, intptr_t value);
+
+/**
+ * Add a NULL-terminated string to a blob, (including the NULL terminator).
+ *
+ * \return True unless allocation failed.
+ */
+bool
+blob_write_string(struct blob *blob, const char *str);
+
+/**
+ * Start reading a blob, (initializing the contents of \blob for reading).
+ *
+ * After this call, the caller can use the various blob_read_* functions to
+ * read elements from the data array.
+ *
+ * For all of the blob_read_* functions, if there is insufficient data
+ * remaining, the functions will do nothing, (perhaps returning default values
+ * such as 0). The caller can detect this by noting that the blob_reader's
+ * current value is unchanged before and after the call.
+ */
+void
+blob_reader_init(struct blob_reader *blob, uint8_t *data, size_t size);
+
+/**
+ * Read some unstructured, fixed-size data from the current location, (and
+ * update the current location to just past this data).
+ *
+ * \note The memory returned belongs to the data underlying the blob reader. The
+ * caller must copy the data in order to use it after the lifetime of the data
+ * underlying the blob reader.
+ *
+ * \return The bytes read (see note above about memory lifetime).
+ */
+void *
+blob_read_bytes(struct blob_reader *blob, size_t size);
+
+/**
+ * Read some unstructured, fixed-size data from the current location, copying
+ * it to \dest (and update the current location to just past this data)
+ */
+void
+blob_copy_bytes(struct blob_reader *blob, uint8_t *dest, size_t size);
+
+/**
+ * Read a uint32_t from the current location, (and update the current location
+ * to just past this uint32_t).
+ *
+ * \note This function will only read from a uint32_t-aligned offset from the
+ * beginning of the blob's data, so some padding bytes may be skipped.
+ *
+ * \return The uint32_t read
+ */
+uint32_t
+blob_read_uint32(struct blob_reader *blob);
+
+/**
+ * Read a uint64_t from the current location, (and update the current location
+ * to just past this uint64_t).
+ *
+ * \note This function will only read from a uint64_t-aligned offset from the
+ * beginning of the blob's data, so some padding bytes may be skipped.
+ *
+ * \return The uint64_t read
+ */
+uint64_t
+blob_read_uint64(struct blob_reader *blob);
+
+/**
+ * Read an intptr_t value from the current location, (and update the
+ * current location to just past this intptr_t).
+ *
+ * \note This function will only read from an intptr_t-aligned offset from the
+ * beginning of the blob's data, so some padding bytes may be skipped.
+ *
+ * \return The intptr_t read
+ */
+intptr_t
+blob_read_intptr(struct blob_reader *blob);
+
+/**
+ * Read a NULL-terminated string from the current location, (and update the
+ * current location to just past this string).
+ *
+ * \note The memory returned belongs to the data underlying the blob reader. The
+ * caller must copy the string in order to use the string after the lifetime
+ * of the data underlying the blob reader.
+ *
+ * \return The string read (see note above about memory lifetime). However, if
+ * there is no NULL byte remaining within the blob, this function returns
+ * NULL.
+ */
+char *
+blob_read_string(struct blob_reader *blob);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* BLOB_H */