Add HPACK decoder public API

lib/includes/nghttp2/nghttp2.h

@@ -2842,6 +2842,122 @@ int nghttp2_check_header_name(const uint8_t *name, size_t len);
  */
 int nghttp2_check_header_value(const uint8_t *value, size_t len);
 
+/* HPACK API */
+
+struct nghttp2_hd_inflater;
+
+/**
+ * @struct
+ *
+ * HPACK inflater object.
+ */
+typedef struct nghttp2_hd_inflater nghttp2_hd_inflater;
+
+/**
+ * @function
+ *
+ * Initializes |*inflater_ptr| for inflating name/values pairs.
+ *
+ * This function returns 0 if it succeeds, or one of the following
+ * negative error codes:
+ *
+ * :enum:`NGHTTP2_ERR_NOMEM`
+ *     Out of memory.
+ */
+int nghttp2_hd_inflate_new(nghttp2_hd_inflater **inflater_ptr);
+
+/**
+ * @function
+ *
+ * Deallocates any resources allocated for |inflater|.
+ */
+void nghttp2_hd_inflate_del(nghttp2_hd_inflater *inflater);
+
+/**
+ * @function
+ *
+ * Changes header table size in the |inflater|. This may trigger
+ * eviction in the dynamic table.
+ *
+ * The |settings_hd_table_bufsize_max| should be the value transmitted
+ * in SETTINGS_HEADER_TABLE_SIZE.
+ *
+ * This function returns 0 if it succeeds, or one of the following
+ * negative error codes:
+ *
+ * :enum:`NGHTTP2_ERR_NOMEM`
+ *     Out of memory.
+ */
+int nghttp2_hd_inflate_change_table_size(nghttp2_hd_inflater *inflater,
+                                         size_t settings_hd_table_bufsize_max);
+
+/**
+ * @enum
+ *
+ * The flags for header inflation.
+ */
+typedef enum {
+  /**
+   * No flag set.
+   */
+  NGHTTP2_HD_INFLATE_NONE = 0,
+  /**
+   * Indicates all headers were inflated.
+   */
+  NGHTTP2_HD_INFLATE_FINAL = 1,
+  /**
+   * Indicates a header was emitted.
+   */
+  NGHTTP2_HD_INFLATE_EMIT = (1 << 1)
+} nghttp2_hd_inflate_flag;
+
+/**
+ * @function
+ *
+ * Inflates name/value block stored in |in| with length |inlen|. This
+ * function performs decompression. For each successful emission of
+ * header name/value pair, :enum:`NGHTTP2_HD_INFLATE_EMIT` is set in
+ * |*inflate_flags| and name/value pair is assigned to the |nv_out|
+ * and the function returns. The caller must not free the members of
+ * |nv_out|.
+ *
+ * The |nv_out| may include pointers to the memory region in the
+ * |in|. The caller must retain the |in| while the |nv_out| is used.
+ *
+ * The application should call this function repeatedly until the
+ * `(*inflate_flags) & NGHTTP2_HD_INFLATE_FINAL` is nonzero and return
+ * value is non-negative. This means the all input values are
+ * processed successfully. Then the application must call
+ * `nghttp2_hd_inflate_end_headers()` to prepare for the next header
+ * block input.
+ *
+ * The caller can feed complete compressed header block. It also can
+ * feed it in several chunks. The caller must set |in_final| to
+ * nonzero if the given input is the last block of the compressed
+ * header.
+ *
+ * This function returns the number of bytes processed if it succeeds,
+ * or one of the following negative error codes:
+ *
+ * :enum:`NGHTTP2_ERR_NOMEM`
+ *     Out of memory.
+ * :enum:`NGHTTP2_ERR_HEADER_COMP`
+ *     Inflation process has failed.
+ */
+ssize_t nghttp2_hd_inflate_hd(nghttp2_hd_inflater *inflater,
+                              nghttp2_nv *nv_out, int *inflate_flags,
+                              uint8_t *in, size_t inlen, int in_final);
+
+/**
+ * @function
+ *
+ * Signals the end of decompression for one header block.
+ *
+ * This function returns 0 if it succeeds. Currently this function
+ * always succeeds.
+ */
+int nghttp2_hd_inflate_end_headers(nghttp2_hd_inflater *inflater);
+
 #ifdef __cplusplus
 }
 #endif

lib/nghttp2_hd.c

@@ -1920,6 +1920,24 @@ int nghttp2_hd_inflate_end_headers(nghttp2_hd_inflater *inflater)
   return 0;
 }
 
+int nghttp2_hd_inflate_new(nghttp2_hd_inflater **inflater_ptr)
+{
+  *inflater_ptr = malloc(sizeof(nghttp2_hd_inflater));
+
+  if(*inflater_ptr == NULL) {
+    return NULL;
+  }
+
+  return nghttp2_hd_inflate_init(*inflater_ptr);
+}
+
+void nghttp2_hd_inflate_del(nghttp2_hd_inflater *inflater)
+{
+  nghttp2_hd_inflate_free(inflater);
+
+  free(inflater);
+}
+
 int nghttp2_hd_emit_indname_block(nghttp2_bufs *bufs, size_t index,
                                   nghttp2_nv *nv, int inc_indexing)
 {

lib/nghttp2_hd.h

@@ -142,7 +142,7 @@ typedef struct {
   uint8_t no_refset;
 } nghttp2_hd_deflater;
 
-typedef struct {
+struct nghttp2_hd_inflater {
   nghttp2_hd_context ctx;
   /* header name buffer */
   nghttp2_bufs namebufs;
@@ -180,7 +180,7 @@ typedef struct {
   /* nonzero if deflater requires that current entry must not be
      indexed */
   uint8_t no_index;
-} nghttp2_hd_inflater;
+};
 
 /*
  * Initializes the |ent| members. If NGHTTP2_HD_FLAG_NAME_ALLOC bit
@@ -233,27 +233,11 @@ int nghttp2_hd_deflate_init(nghttp2_hd_deflater *deflater);
 int nghttp2_hd_deflate_init2(nghttp2_hd_deflater *deflater,
                              size_t deflate_hd_table_bufsize_max);
 
-/*
- * Initializes |inflater| for inflating name/values pairs.
- *
- * This function returns 0 if it succeeds, or one of the following
- * negative error codes:
- *
- * NGHTTP2_ERR_NOMEM
- *     Out of memory.
- */
-int nghttp2_hd_inflate_init(nghttp2_hd_inflater *inflater);
-
 /*
  * Deallocates any resources allocated for |deflater|.
  */
 void nghttp2_hd_deflate_free(nghttp2_hd_deflater *deflater);
 
-/*
- * Deallocates any resources allocated for |inflater|.
- */
-void nghttp2_hd_inflate_free(nghttp2_hd_inflater *inflater);
-
 /*
  * Sets the availability of reference set in the |deflater|. If
  * |no_refset| is nonzero, the deflater will first emit index=0 in the
@@ -279,23 +263,6 @@ void nghttp2_hd_deflate_set_no_refset(nghttp2_hd_deflater *deflater,
 int nghttp2_hd_deflate_change_table_size(nghttp2_hd_deflater *deflater,
                                          size_t settings_hd_table_bufsize_max);
 
-/*
- * Changes header table size in the |inflater|. This may trigger
- * eviction in the dynamic table.
- *
- * The |settings_hd_table_bufsize_max| should be the value transmitted
- * in SETTINGS_HEADER_TABLE_SIZE.
- *
- * This function returns 0 if it succeeds, or one of the following
- * negative error codes:
- *
- * NGHTTP2_ERR_NOMEM
- *     Out of memory.
- */
-int nghttp2_hd_inflate_change_table_size(nghttp2_hd_inflater *inflater,
-                                         size_t settings_hd_table_bufsize_max);
-
-
 /*
  * Deflates the |nva|, which has the |nvlen| name/value pairs, into
  * the |bufs|.
@@ -322,54 +289,21 @@ int nghttp2_hd_deflate_hd(nghttp2_hd_deflater *deflater,
                           nghttp2_bufs *bufs,
                           nghttp2_nv *nva, size_t nvlen);
 
-typedef enum {
-  NGHTTP2_HD_INFLATE_NONE = 0,
-  NGHTTP2_HD_INFLATE_FINAL = 1,
-  NGHTTP2_HD_INFLATE_EMIT = (1 << 1)
-} nghttp2_hd_inflate_flag;
-
 /*
- * Inflates name/value block stored in |in| with length |inlen|. This
+ * Initializes |inflater| for inflating name/values pairs.
- * function performs decompression. For each successful emission of
- * header name/value pair, NGHTTP2_HD_INFLATE_EMIT is set in
- * |*inflate_flags| and name/value pair is assigned to the |nv_out|
- * and the function returns. The caller must not free the members of
- * |nv_out|.
  *
- * The |nv_out| may include pointers to the memory region in the
+ * This function returns 0 if it succeeds, or one of the following
- * |in|. The caller must retain the |in| while the |nv_out| is used.
+ * negative error codes:
  *
- * The application should call this function repeatedly until the
+ * :enum:`NGHTTP2_ERR_NOMEM`
- * |(*inflate_flags) & NGHTTP2_HD_INFLATE_FINAL| is nonzero and return
- * value is non-negative. This means the all input values are
- * processed successfully. Then the application must call
- * `nghttp2_hd_inflate_end_headers()` to prepare for the next header
- * block input.
- *
- * The caller can feed complete compressed header block. It also can
- * feed it in several chunks. The caller must set |in_final| to
- * nonzero if the given input is the last block of the compressed
- * header.
- *
- * This function returns the number of bytes processed if it succeeds,
- * or one of the following negative error codes:
- *
- * NGHTTP2_ERR_NOMEM
  *     Out of memory.
- * NGHTTP2_ERR_HEADER_COMP
- *     Inflation process has failed.
  */
-ssize_t nghttp2_hd_inflate_hd(nghttp2_hd_inflater *inflater,
+int nghttp2_hd_inflate_init(nghttp2_hd_inflater *inflater);
-                              nghttp2_nv *nv_out, int *inflate_flags,
-                              uint8_t *in, size_t inlen, int in_final);
 
 /*
- * Signals the end of decompression for one header block.
+ * Deallocates any resources allocated for |inflater|.
- *
- * This function returns 0 if it succeeds. Currently this function
- * always succeeds.
  */
-int nghttp2_hd_inflate_end_headers(nghttp2_hd_inflater *inflater);
+void nghttp2_hd_inflate_free(nghttp2_hd_inflater *inflater);
 
 /* For unittesting purpose */
 int nghttp2_hd_emit_indname_block(nghttp2_bufs *bufs, size_t index,