ucx/cx/properties.h

changeset 101
7b3a3130be44
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ucx/cx/properties.h	Mon Jan 06 22:22:55 2025 +0100
@@ -0,0 +1,644 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2024 Mike Becker, Olaf Wintermann All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   1. Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *
+ *   2. Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in the
+ *      documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+/**
+ * @file properties.h
+ * @brief Interface for parsing data from properties files.
+ * @author Mike Becker
+ * @author Olaf Wintermann
+ * @copyright 2-Clause BSD License
+ */
+
+#ifndef UCX_PROPERTIES_H
+#define UCX_PROPERTIES_H
+
+#include "common.h"
+#include "string.h"
+#include "map.h"
+#include "buffer.h"
+
+#include <stdio.h>
+#include <string.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * Configures the expected characters for the properties parser.
+ */
+struct cx_properties_config_s {
+    /**
+     * The key/value delimiter that shall be used.
+     * This is '=' by default.
+     */
+    char delimiter;
+
+    /**
+     * The character, when appearing at the end of a line, continues that line.
+     * This is '\' by default.
+     */
+    // char continuation; // TODO: line continuation in properties
+
+    /**
+     * The first comment character.
+     * This is '#' by default.
+     */
+    char comment1;
+
+    /**
+     * The second comment character.
+     * This is not set by default.
+     */
+    char comment2;
+
+    /**
+     * The third comment character.
+     * This is not set by default.
+     */
+    char comment3;
+};
+
+/**
+ * Typedef for the properties config.
+ */
+typedef struct cx_properties_config_s CxPropertiesConfig;
+
+/**
+ * Default properties configuration.
+ */
+extern const CxPropertiesConfig cx_properties_config_default;
+
+/**
+ * Status codes for the properties interface.
+ */
+enum cx_properties_status {
+    /**
+     * Everything is fine.
+     */
+    CX_PROPERTIES_NO_ERROR,
+    /**
+     * The input buffer does not contain more data.
+     */
+    CX_PROPERTIES_NO_DATA,
+    /**
+     * The input ends unexpectedly.
+     *
+     * This either happens when the last line does not terminate with a line
+     * break, or when the input ends with a parsed key but no value.
+     */
+    CX_PROPERTIES_INCOMPLETE_DATA,
+    /**
+     * Not used as a status and never returned by any function.
+     *
+     * You can use this enumerator to check for all "good" status results
+     * by checking if the status is less than @c CX_PROPERTIES_OK.
+     *
+     * A "good" status means, that you can refill data and continue parsing.
+     */
+    CX_PROPERTIES_OK,
+    /**
+     * Input buffer is @c NULL.
+     */
+    CX_PROPERTIES_NULL_INPUT,
+    /**
+     * The line contains a delimiter, but no key.
+     */
+    CX_PROPERTIES_INVALID_EMPTY_KEY,
+    /**
+     * The line contains data, but no delimiter.
+     */
+    CX_PROPERTIES_INVALID_MISSING_DELIMITER,
+    /**
+     * More internal buffer was needed, but could not be allocated.
+     */
+    CX_PROPERTIES_BUFFER_ALLOC_FAILED,
+    /**
+     * Initializing the properties source failed.
+     *
+     * @see cx_properties_read_init_func
+     */
+    CX_PROPERTIES_READ_INIT_FAILED,
+    /**
+     * Reading from a properties source failed.
+     *
+     * @see cx_properties_read_func
+     */
+    CX_PROPERTIES_READ_FAILED,
+    /**
+     * Sinking a k/v-pair failed.
+     *
+     * @see cx_properties_sink_func
+     */
+    CX_PROPERTIES_SINK_FAILED,
+};
+
+/**
+ * Typedef for the properties status enum.
+ */
+typedef enum cx_properties_status CxPropertiesStatus;
+
+/**
+ * Interface for working with properties data.
+ */
+struct cx_properties_s {
+    /**
+     * The configuration.
+     */
+    CxPropertiesConfig config;
+
+    /**
+     * The text input buffer.
+     */
+    CxBuffer input;
+
+    /**
+     * Internal buffer.
+     */
+    CxBuffer buffer;
+};
+
+/**
+ * Typedef for the properties interface.
+ */
+typedef struct cx_properties_s CxProperties;
+
+
+/**
+ * Typedef for a properties sink.
+ */
+typedef struct cx_properties_sink_s CxPropertiesSink;
+
+/**
+ * A function that consumes a k/v-pair in a sink.
+ *
+ * The sink could be e.g. a map and the sink function would be calling
+ * a map function to store the k/v-pair.
+ *
+ * @param prop the properties interface that wants to sink a k/v-pair
+ * @param sink the sink
+ * @param key the key
+ * @param value the value
+ * @retval zero success
+ * @retval non-zero sinking the k/v-pair failed
+ */
+cx_attr_nonnull
+typedef int(*cx_properties_sink_func)(
+        CxProperties *prop,
+        CxPropertiesSink *sink,
+        cxstring key,
+        cxstring value
+);
+
+/**
+ * Defines a sink for k/v-pairs.
+ */
+struct cx_properties_sink_s {
+    /**
+     * The sink object.
+     */
+    void *sink;
+    /**
+     * Optional custom data.
+     */
+    void *data;
+    /**
+     * A function for consuming k/v-pairs into the sink.
+     */
+    cx_properties_sink_func sink_func;
+};
+
+
+/**
+ * Typedef for a properties source.
+ */
+typedef struct cx_properties_source_s CxPropertiesSource;
+
+/**
+ * A function that reads data from a source.
+ *
+ * When the source is depleted, implementations SHALL provide an empty
+ * string in the @p target and return zero.
+ * A non-zero return value is only permitted in case of an error.
+ *
+ * The meaning of the optional parameters is implementation-dependent.
+ *
+ * @param prop the properties interface that wants to read from the source
+ * @param src the source
+ * @param target a string buffer where the read data shall be stored
+ * @retval zero success
+ * @retval non-zero reading the data failed
+ */
+cx_attr_nonnull
+typedef int(*cx_properties_read_func)(
+        CxProperties *prop,
+        CxPropertiesSource *src,
+        cxstring *target
+);
+
+/**
+ * A function that may initialize additional memory for the source.
+ *
+ * @param prop the properties interface that wants to read from the source
+ * @param src the source
+ * @retval zero initialization was successful
+ * @retval non-zero otherwise
+ */
+cx_attr_nonnull
+typedef int(*cx_properties_read_init_func)(
+        CxProperties *prop,
+        CxPropertiesSource *src
+);
+
+/**
+ * A function that cleans memory initialized by the read_init_func.
+ *
+ * @param prop the properties interface that wants to read from the source
+ * @param src the source
+ */
+cx_attr_nonnull
+typedef void(*cx_properties_read_clean_func)(
+        CxProperties *prop,
+        CxPropertiesSource *src
+);
+
+/**
+ * Defines a properties source.
+ */
+struct cx_properties_source_s {
+    /**
+     * The source object.
+     *
+     * For example a file stream or a string.
+     */
+    void *src;
+    /**
+     * Optional additional data pointer.
+     */
+    void *data_ptr;
+    /**
+     * Optional size information.
+     */
+    size_t data_size;
+    /**
+     * A function that reads data from the source.
+     */
+    cx_properties_read_func read_func;
+    /**
+     * Optional function that may prepare the source for reading data.
+     */
+    cx_properties_read_init_func read_init_func;
+    /**
+     * Optional function that cleans additional memory allocated by the
+     * read_init_func.
+     */
+    cx_properties_read_clean_func read_clean_func;
+};
+
+/**
+ * Initialize a properties interface.
+ *
+ * @param prop the properties interface
+ * @param config the properties configuration
+ * @see cxPropertiesInitDefault()
+ */
+cx_attr_nonnull
+void cxPropertiesInit(CxProperties *prop, CxPropertiesConfig config);
+
+/**
+ * Destroys the properties interface.
+ *
+ * @note Even when you are certain that you did not use the interface in a
+ * way that caused a memory allocation, you should call this function anyway.
+ * Future versions of the library might add features that need additional memory
+ * and you really don't want to search the entire code where you might need
+ * add call to this function.
+ *
+ * @param prop the properties interface
+ */
+cx_attr_nonnull
+void cxPropertiesDestroy(CxProperties *prop);
+
+/**
+ * Destroys and re-initializes the properties interface.
+ *
+ * You might want to use this, to reset the parser after
+ * encountering a syntax error.
+ *
+ * @param prop the properties interface
+ */
+cx_attr_nonnull
+static inline void cxPropertiesReset(CxProperties *prop) {
+    CxPropertiesConfig config = prop->config;
+    cxPropertiesDestroy(prop);
+    cxPropertiesInit(prop, config);
+}
+
+/**
+ * Initialize a properties parser with the default configuration.
+ *
+ * @param prop (@c CxProperties*) the properties interface
+ * @see cxPropertiesInit()
+ */
+#define cxPropertiesInitDefault(prop) \
+    cxPropertiesInit(prop, cx_properties_config_default)
+
+/**
+ * Fills the input buffer with data.
+ *
+ * After calling this function, you can parse the data by calling
+ * cxPropertiesNext().
+ *
+ * @remark The properties interface tries to avoid allocations.
+ * When you use this function and cxPropertiesNext() interleaving,
+ * no allocations are performed. However, you must not free the
+ * pointer to the data in that case. When you invoke the fill
+ * function more than once before calling cxPropertiesNext(),
+ * the additional data is appended - inevitably leading to
+ * an allocation of a new buffer and copying the previous contents.
+ *
+ * @param prop the properties interface
+ * @param buf a pointer to the data
+ * @param len the length of the data
+ * @retval zero success
+ * @retval non-zero a memory allocation was necessary but failed
+ * @see cxPropertiesFill()
+ */
+cx_attr_nonnull
+cx_attr_access_r(2, 3)
+int cxPropertiesFilln(
+        CxProperties *prop,
+        const char *buf,
+        size_t len
+);
+
+#ifdef __cplusplus
+} // extern "C"
+cx_attr_nonnull
+static inline int cxPropertiesFill(
+        CxProperties *prop,
+        cxstring str
+) {
+    return cxPropertiesFilln(prop, str.ptr, str.length);
+}
+
+cx_attr_nonnull
+static inline int cxPropertiesFill(
+        CxProperties *prop,
+        cxmutstr str
+) {
+    return cxPropertiesFilln(prop, str.ptr, str.length);
+}
+
+cx_attr_nonnull
+cx_attr_cstr_arg(2)
+static inline int cxPropertiesFill(
+        CxProperties *prop,
+        const char *str
+) {
+    return cxPropertiesFilln(prop, str, strlen(str));
+}
+
+extern "C" {
+#else // __cplusplus
+/**
+ * Fills the input buffer with data.
+ *
+ * After calling this function, you can parse the data by calling
+ * cxPropertiesNext().
+ *
+ * @attention The properties interface tries to avoid allocations.
+ * When you use this function and cxPropertiesNext() interleaving,
+ * no allocations are performed. However, you must not free the
+ * pointer to the data in that case. When you invoke the fill
+ * function more than once before calling cxPropertiesNext(),
+ * the additional data is appended - inevitably leading to
+ * an allocation of a new buffer and copying the previous contents.
+ *
+ * @param prop the properties interface
+ * @param str the text to fill in
+ * @retval zero success
+ * @retval non-zero a memory allocation was necessary but failed
+ * @see cxPropertiesFilln()
+ */
+#define cxPropertiesFill(prop, str) _Generic((str), \
+    cxstring: cx_properties_fill_cxstr,             \
+    cxmutstr: cx_properties_fill_mutstr,            \
+    char*: cx_properties_fill_str,                  \
+    const char*: cx_properties_fill_str)            \
+    (prop, str)
+
+/**
+ * @copydoc cxPropertiesFill()
+ */
+cx_attr_nonnull
+static inline int cx_properties_fill_cxstr(
+        CxProperties *prop,
+        cxstring str
+) {
+    return cxPropertiesFilln(prop, str.ptr, str.length);
+}
+
+/**
+ * @copydoc cxPropertiesFill()
+ */
+cx_attr_nonnull
+static inline int cx_properties_fill_mutstr(
+        CxProperties *prop,
+        cxmutstr str
+) {
+    return cxPropertiesFilln(prop, str.ptr, str.length);
+}
+
+/**
+ * @copydoc cxPropertiesFill()
+ */
+cx_attr_nonnull
+cx_attr_cstr_arg(2)
+static inline int cx_properties_fill_str(
+        CxProperties *prop,
+        const char *str
+) {
+    return cxPropertiesFilln(prop, str, strlen(str));
+}
+#endif
+
+/**
+ * Specifies stack memory that shall be used as internal buffer.
+ *
+ * @param prop the properties interface
+ * @param buf a pointer to stack memory
+ * @param capacity the capacity of the stack memory
+ */
+cx_attr_nonnull
+void cxPropertiesUseStack(
+        CxProperties *prop,
+        char *buf,
+        size_t capacity
+);
+
+/**
+ * Retrieves the next key/value-pair.
+ *
+ * This function returns zero as long as there are key/value-pairs found.
+ * If no more key/value-pairs are found, #CX_PROPERTIES_NO_DATA is returned.
+ *
+ * When an incomplete line is encountered, #CX_PROPERTIES_INCOMPLETE_DATA is
+ * returned, and you can add more data with #cxPropertiesFill().
+ *
+ * @remark The incomplete line will be stored in an internal buffer, which is
+ * allocated on the heap, by default. If you want to avoid allocations,
+ * you can specify sufficient space with cxPropertiesUseStack() after
+ * initialization with cxPropertiesInit().
+ *
+ * @attention The returned strings will point into a buffer that might not be
+ * available later. It is strongly recommended to copy the strings for further
+ * use.
+ *
+ * @param prop the properties interface
+ * @param key a pointer to the cxstring that shall contain the property name
+ * @param value a pointer to the cxstring that shall contain the property value
+ * @retval CX_PROPERTIES_NO_ERROR (zero) a key/value pair was found
+ * @retval CX_PROPERTIES_NO_DATA there is no (more) data in the input buffer
+ * @retval CX_PROPERTIES_INCOMPLETE_DATA the data in the input buffer is incomplete
+ * (fill more data and try again)
+ * @retval CX_PROPERTIES_NULL_INPUT the input buffer was never filled
+ * @retval CX_PROPERTIES_INVALID_EMPTY_KEY the properties data contains an illegal empty key
+ * @retval CX_PROPERTIES_INVALID_MISSING_DELIMITER the properties data contains a line without delimiter
+ * @retval CX_PROPERTIES_BUFFER_ALLOC_FAILED an internal allocation was necessary but failed
+ */
+cx_attr_nonnull
+cx_attr_nodiscard
+CxPropertiesStatus cxPropertiesNext(
+        CxProperties *prop,
+        cxstring *key,
+        cxstring *value
+);
+
+/**
+ * Creates a properties sink for an UCX map.
+ *
+ * The values stored in the map will be pointers to strings allocated
+ * by #cx_strdup_a().
+ * The default stdlib allocator will be used, unless you specify a custom
+ * allocator in the optional @c data of the sink.
+ *
+ * @param map the map that shall consume the k/v-pairs.
+ * @return the sink
+ * @see cxPropertiesLoad()
+ */
+cx_attr_nonnull
+cx_attr_nodiscard
+CxPropertiesSink cxPropertiesMapSink(CxMap *map);
+
+/**
+ * Creates a properties source based on an UCX string.
+ *
+ * @param str the string
+ * @return the properties source
+ * @see cxPropertiesLoad()
+ */
+cx_attr_nodiscard
+CxPropertiesSource cxPropertiesStringSource(cxstring str);
+
+/**
+ * Creates a properties source based on C string with the specified length.
+ *
+ * @param str the string
+ * @param len the length
+ * @return the properties source
+ * @see cxPropertiesLoad()
+ */
+cx_attr_nonnull
+cx_attr_nodiscard
+cx_attr_access_r(1, 2)
+CxPropertiesSource cxPropertiesCstrnSource(const char *str, size_t len);
+
+/**
+ * Creates a properties source based on a C string.
+ *
+ * The length will be determined with strlen(), so the string MUST be
+ * zero-terminated.
+ *
+ * @param str the string
+ * @return the properties source
+ * @see cxPropertiesLoad()
+ */
+cx_attr_nonnull
+cx_attr_nodiscard
+cx_attr_cstr_arg(1)
+CxPropertiesSource cxPropertiesCstrSource(const char *str);
+
+/**
+ * Creates a properties source based on an FILE.
+ *
+ * @param file the file
+ * @param chunk_size how many bytes may be read in one operation
+ *
+ * @return the properties source
+ * @see cxPropertiesLoad()
+ */
+cx_attr_nonnull
+cx_attr_nodiscard
+cx_attr_access_r(1)
+CxPropertiesSource cxPropertiesFileSource(FILE *file, size_t chunk_size);
+
+
+/**
+ * Loads properties data from a source and transfers it to a sink.
+ *
+ * This function tries to read as much data from the source as possible.
+ * When the source was completely consumed and at least on k/v-pair was found,
+ * the return value will be #CX_PROPERTIES_NO_ERROR.
+ * When the source was consumed but no k/v-pairs were found, the return value
+ * will be #CX_PROPERTIES_NO_DATA.
+ * The other result codes apply, according to their description.
+ *
+ * @param prop the properties interface
+ * @param sink the sink
+ * @param source the source
+ * @retval CX_PROPERTIES_NO_ERROR (zero) a key/value pair was found
+ * @retval CX_PROPERTIES_READ_INIT_FAILED initializing the source failed
+ * @retval CX_PROPERTIES_READ_FAILED reading from the source failed
+ * @retval CX_PROPERTIES_SINK_FAILED sinking the properties into the sink failed
+ * @retval CX_PROPERTIES_NO_DATA the source did not provide any key/value pairs
+ * @retval CX_PROPERTIES_INVALID_EMPTY_KEY the properties data contains an illegal empty key
+ * @retval CX_PROPERTIES_INVALID_MISSING_DELIMITER the properties data contains a line without delimiter
+ * @retval CX_PROPERTIES_BUFFER_ALLOC_FAILED an internal allocation was necessary but failed
+ */
+cx_attr_nonnull
+CxPropertiesStatus cxPropertiesLoad(
+        CxProperties *prop,
+        CxPropertiesSink sink,
+        CxPropertiesSource source
+);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif // UCX_PROPERTIES_H

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